Ladies: simply using birth control is not always enough to prevent an unintended pregnancy.
According to numbers from the Association of Reproductive Health Professionals, failure rates for popular contraceptives like the pill and male condom can be as high as 9 and 18 percent. And some methods of birth control, like the sponge or the female condom, have higher than ideal failure rates even when they’re used perfectly—5 and 20 percent, respectively.
Chances are you will be fine if you choose the right type of birth control, and use it correctly. The pill, for example, only has a .3 percent failure rate when it’s taken as instructed (so remember to set your alarm). And an IUD, which requires little maintenance, only fails .8 to .6 percent of the time.
If you’re curious about the effectiveness for the birth control you use, see the chart below. Note that when a method of birth control is used correctly and consistently, the Centers for Disease Control and Prevention defines this as perfect use. Typical use measures how effective the method is in actuality, including inconsistent and incorrect use.