If taken properly, birth control pills are 99.9 percent effective (relieving, right?). But taking them effectively includes timing them right, storing them properly, and making sure your body is clear of other drugs or chemicals that could interact with your hormones and throw your body off whack. With so many things that can have a slight effect, from common medication to everyday foods, it can be hard to tell if we really our taking that pill effectively. If we aren’t, it can be equally difficult to pinpoint where we’re going wrong.