In general, birth control pills are about 91% effective at preventing pregnancy. This isn’t 100% because of human error in dosing and, well, nothing’s perfect! So if you want to improve the efficacy, consider a couple of things. First, a condom. Of course I recommend a condom regardless because it helps prevent the spread of STIs, but it can also, when used correctly, increase efficacy of birth control pills to 98.4%. Second, use the pull-out (withdrawal) method! When combined with birth control pills, the efficacy at preventing pregnancy increases to 98%. Pretty darn good, right?