So why do the placebo pills exist? Back in the early days of birth control's conception, one of its champions—a doctor and devout Catholic named John Rock—was desperate for the Pope to approve of its use. So he designed the medication to mimic a "natural cycle," spinning the pill as a way to regulate menstrual bleeding and fertility instead of halting ovulation. At the time, the only birth control the church accepted was the rhythm method, where individuals had to monitor their menstrual cycle to make sure they abstained from sex while fertile. Even with modern-day apps and other technological assistance, this kind of fertility tracking is incredibly difficult for most people. The pill, Rock suggested, was merely a way to "regulate" these finicky and hard-to-track periods so that Catholics could reliably know when they should abstain. The problem, of course, was that the pill prevented ovulation and menstruation. That's where the week of sugar pills—and the resulting not-actually-a-period-bleed—came into play.