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Updated Dec 20, 2021 11:03 AM

If you’ve ever tried to buy a pregnancy test, you’ve probably stared down the pharmacy aisle and noticed a dizzying amount of options. Unfortunately, there’s a good chance that if you think you might be pregnant, you’re already on-edge, and all the choices can go from confusing to overwhelming. You might wonder what differences there are between the tests, and if those features really matter. Should you get a manual or digital test? What about a pack of low-tech, paper strips? And most importantly, will the test you pick give you your answer accurately and quickly? While all tests work fundamentally the same way, a few key differences can help you hone in on what are actually the best pregnancy tests. Here’s what you should need to know.

How we chose the best pregnancy tests

To understand the science behind pregnancy tests, we talked to three OB-GYN doctors, two pathologists who are experts in the chemistry of pregnancy testing, and three certified nurse-midwives. For our top picks, we mainly looked at tests included in scientific studies, including this one published in the Journal Immunoassay and Immunochemistry in 2019, on over-the-counter pregnancy tests. We also considered customer reviews and factors like cost per test, ease of use, and readability. 

Because most pregnancy tests are reasonably effective, there isn’t much scientific incentive to independently examine them. The most recent independent study of over-the-counter pregnancy tests in the United States is from 2011, and since then, research on these tests has been conducted mostly by companies that produce the tests. This creates an obvious conflict of interest. Even the author of the 2011 study has had papers removed from journals (though not the study discussed here) over failure to disclose funding from companies that manufacture the tests. 

We have chosen to consider scientific studies in trying to identify the best pregnancy tests, including those where there may be a conflict of interest, which were published in scientific journals. These studies were subject to a review process by other scientists, and all conflicts of interests were disclosed.

Things to consider before buying a pregnancy test

Despite small differences between them, all over-the-counter pregnancy tests work basically the same way. They detect a hormone called human chorionic gonadotropin, or hCG, in urine, which the body starts producing when a fertilized egg implants in the lining of the uterus and an embryo begins to grow. Even urine-based pregnancy tests used in doctor’s offices tap the same mechanism. “Anything that’s detecting the pregnancy hormone from the urine is going to be the same, whether you get it from us, or if you get it from a drug store test that you take at home,” says Dr. Sarah Horvath, an obstetrician-gynecologist at Penn State Milton S. Hershey Medical Center. 

There are two main forms of “intact” hCG: regular hCG and hyperglycosylated hCG (hCG-h), which is more common in very early pregnancy. Most tests should detect total hCG, including both types, though some research suggests that many don’t detect hCG-h as effectively.  

Scientifically, pregnancy screenings are a type of test called a lateral flow test. After a sample is collected, it flows to an area with a line of lab-manufactured antibodies that capture a molecular part of hCG called the beta subunit. If it is detected, the hormone will also bind to a second antibody that captures the alpha subunit, the other half of the hCG molecule, which turns the test line a color. The sample will also flow to a control line, which will react to the presence of any urine no matter what to indicate you have used the test correctly.  

That said, there are important things you should be looking at when trying to ID the best pregnancy tests, besides the brand. As with anything at the pharmacy, make sure that the box is sealed and that the test has not expired. 

Ease of use

Read the directions to make sure you will find the test easy to use and that you know when you should be taking it. Most tests work very similarly: Either you pee directly on the stick or you go in a cup and dip the test in the urine. Many people find the first type easier to use and read, though it depends what you prefer. 

Manual vs. digital readings 

It might be that you want to know the results of your test more quickly, in which case manual tests—that is, the non-electronic kind that will give you a line or two—are usually better. Many kinds can give you a result in about a minute, though some can take longer. They’re also cheaper. As are the ultra-manual test strips, which are essentially the same product but without the wand.

If you know you’re going to be second-guessing yourself squinting at results, you might want to opt for a digital test. This kind will deliver a text result, like “pregnant” or “not pregnant.” Digital tests typically take around three to five minutes. The tests use exactly the same mechanism as manual ones, with the same reactive strips inside, but because they rely on an electronic sensor, the line has to become dark enough for the device to pick up. Though some older research suggests digital tests are more accurate, both customer and professional reviews have found them just as clear as digital ones. 

When you want to test

An important measure of test accuracy is sensitivity. More-sensitive tests are better able to detect pregnancy early, when there is not much hCG in the urine. Sensitivity is measured by the minimum concentration of hCG a test can detect, counted in milli-international units per milliliter (mIU/mL). Boxes won’t necessarily spell this out for you, but ones that tout early detection likely have a lower threshold.

A person who is three weeks pregnant usually has a concentration of between 5 and 50 mIU/mL in their urine. Before this, give or take a few days depending on the person, it would be hard or impossible for any test to determine pregnancy. It’s also important to note that doctors measure pregnancy in weeks from the first day of a person’s last menstrual period, though ovulation and pregnancy doesn’t happen until around two weeks later. This terminology essentially adds two weeks of pregnancy. That means if you are three weeks pregnant, you have actually only been pregnant for around a week. 

Different tests may make different recommendations as to when they work best. For instance, First Response says that their tests work up to six days before a missed period, while other brands, like EPI, say that their tests work five days before. Virtually all tests will claim they are 99 percent accurate from the day of your expected period. Though some research has indicated that this claim is inflated for many tests, it’s certainly true that tests taken on or after the day you miss your period are more likely to be accurate than tests taken earlier. In early pregnancy hCG levels increase quickly, so tests that are not as sensitive may not give you an accurate result if you take them too early. 

The earliest you should test: It’s indeed possible to detect a pregnancy five or six days before a missed period, though hCG levels can vary widely between people, and many healthcare professionals recommend waiting at least until a missed period, if not after, to test. If you are planning on testing before the day of your missed period, make sure to buy a brand that says it can detect a result when you plan to test. 

Particularly with early testing, both test manufacturers and medical professionals recommend doing so in the morning, when hCG in your urine will be the most concentrated from not drinking during the night. You might also want to buy a pack with more tests. 

“If the goal is to detect it as early as you can, then I would urge them to get more than one test,” says Jenifer Fahey, aa certified nurse-midwife at the University of Maryland Medical Center and assistant professor in the department of obstetrics, gynecology, and reproductive sciences at the University of Maryland School of Medicine. If you’re going to test early, she said, you should be prepared to try multiple times.

Cost

If you want to be extra sure the test will work well, go with a common name brand. These tests are likely to be well-made, tested thoroughly, and easier to use. “I wouldn’t purchase them from your dollar store,” says David Grenache, a pathologist and chief scientific officer at TriCore Reference Laboratories, which makes medical tests. 

The best pregnancy tests also come from reputable sellers. You might be suspicious of tests at discount stores because it’s sometimes unclear how the store might store or handle the tests, or what exactly makes them so inexpensive, said Angela Sojobi, a certified nurse-midwife at California State University, Fullerton. For instance, she said the tests might be stored in extreme temperatures. 

If cost is an issue, consider pregnancy test strips. These will give you the best deal, especially if you are planning on testing a lot. Unlike the kind with the wand, dip the treated strips in urine rather than peeing directly onto them. But the core technology is the same, and they will still be effective. 

The best pregnancy tests, according to science:

Best pregnancy test overall: Clearblue Rapid Detection Pregnancy Test

Clearblue

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Why it made the cut: A can’t-miss digital readout and independently verified accuracy make this test a go-to for most people.

Specs:

  • Results in five minutes
  • Works well after missed period
  • Digital readout
  • Available in multi packs

Pros:

  • Unmistakable digital results 
  • Highly accurate
  • Very easy to use

Cons: 

  • Results take longer than manual tests
  • Pricier than analog options

Research over the last decade has found that ClearBlue tests are very sensitive in early pregnancy and that people generally find them easy to read and interpret making it our choice for the best pregnancy test overall. In a 2019 study, researchers at Swiss Precision Diagnostics, which makes Clearblue products, found that more than 99 percent of the time, the Clearblue Rapid Detection Pregnancy Test gave a result that agreed with the expected one. The study used controlled hCG solutions with concentrations of 0 and 25 mIU/ml (Clearblue’s claimed sensitivity), and asked volunteers to interpret the results. In a 2014 study, researchers at Leuven University Hospital in Belgium also found that Clearblue Plus and Digital tests had sensitivities as low as 10 mIU/mL, which was more sensitive than any of the other seven tests they looked at, including two used by healthcare professionals. 

The test was rated the highest out of seven tests commonly available in the United Kingdom in surveys evaluating ease of use, readability, and how much users trusted the perceived test result. Similarly, a 2008 study found that the digital version of the test tended to be more accurate, possibly because results were less likely to be misinterpreted. The study found that when tested with urine with a concentration of 25 mIU/ML of hCG, which corresponds to a few days of pregnancy, the digital tests gave the expected result 100 percent of the time. Other tests, including the manual Clearblue, gave the expected result between 65 and around 90 percent of the time. 

Best pregnancy test for early detection: First Response Early Result Pregnancy Test

First Response

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Why it made the cut: As the best pregnancy test for early detection, First Response is found to be the most sensitive in an independent study, this wand’s manual readout also shows results quickly.

Specs: 

  • Results in three minutes
  • Can work days before missed period 
  • Manual reading
  • Available in multi packs

Pros:

  • Fast results
  • Widely available
  • Very sensitive 

Cons:

  • Accurate results before a missed period not guaranteed 
  • Manual readouts may be harder to read

In a 2011 study of six over-the-counter pregnancy tests, Laurence Cole, a biochemist and former director of the United States hCG reference center at the University of New Mexico, found that all First Response tests were by far the most sensitive test he examined: about 5.5 mIU/mL. For comparison, urine tests used in doctor’s offices don’t usually work below 20 mIU/ML. Cole found that the First Response tests detected 97 percent of pregnancies out of 120 on the day of a missed period, and that the manual and digital tests had nearly identical sensitivities. Cole’s results were similar to the claim of the manufacturer, which is that the test can detect 99 percent of pregnancies on the day of a missed period. 

Though Cole found no notable difference between digital and manual First Response tests, manual tests are quicker to read, though only by a few minutes. They’re also less expensive. So, though there probably isn’t a notable difference in accuracy, a manual test is the way to go if you want the quickest results for the least amount of money. 

Best pregnancy test on a budget: ClinicalGuard HCG Pregnancy Test Strips, 100 count

Clinical Guard

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Why it made the cut: For those who need to screen often, this pack of reactive test strips offers the best pregnancy tests on a budget. 

Specs:

  • Results in five minutes
  • Works well after missed period 
  • Manual readout
  • Available in packs of 20, 25, 50, 100

Pros:

  • Very affordable 
  • Taps same test methodology as wand varieties 

Cons:

  • Can be tricker (and messier) than wand varieties 

If you know you want to get results as early as possible, you’ll likely be taking a lot of tests. If you can’t spend a lot of money and are looking for a simple, low-tech option, you might consider pregnancy test strips. Unlike the kind with the wands, you can’t pee directly on these; instead, you must collect your urine in a cup and dip them. They use the same technology as other pregnancy tests and should still give you good results when used correctly. Most pregnancy strips tend to work very similarly; and reviewers have found the various brands virtually identical. However, if you’re looking to buy in bulk, these are the best deal: at their current price they are about 19 cents per test. You can also buy packs of 20, 25, or 50, which are also cheaper than wand tests and comparable to other test strips. 

FAQs:

Q: How long until a pregnancy test is most accurate?

Pregnancy tests can start to show results when you take one 10 days after ovulation, which is usually four or five days before you would expect to miss your period. Many OB-GYN doctors and midwives recommend that you wait until the day of a missed period, and ideally 3-to-4 days after so that you can be sure the test didn’t just fail to detect low levels of hCG. Even then—and even with the best pregnancy tests on the market—it’s possible you won’t not see a positive result until closer to a couple weeks after your missed period. The longer you wait, the more likely a test is to be accurate. After two weeks from your missed period, if you get negative results, chances are you are not pregnant. If you still believe that you are, you should talk to your healthcare provider. 

Q: How long do tests take to show results? 

When you are taking a pregnancy test, how long you have to wait to see results depends on the test. It could be less than a minute, five minutes, or as long as 10. With manual tests, try not to lose your patience and decide that the test must be done before the time it says on the package. Likewise, you can’t necessarily trust the results if you pull a test you took out of the trash hours later: Some manual tests will have a line appear after a while that does not reflect a positive result. This is a so-called “evaporation line,” which is just a mark made when your urine evaporates from the test and can be mistaken for a positive result. 

Q: Which pregnancy test can detect the earliest?

According to currently available data, First Response tests are the most sensitive and can therefore detect pregnancy the earliest. However, if you have a reason to be concerned about your pregnancy—for instance if you have a history of miscarriage—you should talk to your healthcare provider and they may have you take a serum, or blood pregnancy test. In general, these tests can detect pregnancy earlier than over-the-counter urine tests. And because they measure the amount of hCG, as opposed to its presence, they can give your doctor information about whether your pregnancy might be abnormal or even dangerous due to situations like early miscarriage or an ectopic pregnancy, which could be associated with unusual patterns in hCG levels. 

Q: Can you be 5 weeks pregnant and test negative?

Probably not. Interestingly, Ann Gronowski, a pathologist at the University of Washington in St. Louis, and her colleagues examined in a series of studies how some urine-based pregnancy tests used in healthcare and hospital settings can give false negative results five or more weeks into pregnancy. This is because of a flaw in some tests in which they fail to detect a degraded form of hCG, that becomes more prevalent in the body after five or six weeks of pregnancy. However, this likely isn’t a concern with at-home tests. If you think you are pregnant but continuously test negative, you should talk to a healthcare provider. 

Final thoughts on the best pregnancy tests

Though there are many options when it comes to narrowing what can rank as the best pregnancy tests, First Response and Clearblue tests have the most scientific backing and are likely to be accurate and easy to use. ClinicalGuard pregnancy test strips are a good affordable, buy-in-bulk option. You should also be careful to make sure that tests are sealed, not expired, and sold from a reputable source like a drug store—not a dollar store where it might be unclear how they store and handle items. Make sure to read the directions, be patient, and don’t panic. If you do test positive, you should talk to an OB-GYN doctor or certified midwife, who can help you get the best possible care, no matter your plans for the pregnancy.