Birth control (or contraception) is any method, medicine, or device used to prevent a pregnancy before it starts. There are many different types of birth control. Some work better than others at preventing pregnancy and no method is 100% effective. But your chances of getting pregnant are lower if you use a more effective method.

Primary methods of birth control are meant to be used before sex to prevent a pregnancy. These methods can range from things like condoms (which can be found right at the store without a prescription) to birth control pills or IUDs (which need to be prescribed by your doctor).

Emergency contraception (like Plan B) is a form of birth control that is meant to be used if your primary method failed (like a condom broke or you missed pills) or you forgot to use primary birth control. Plan B is used to help prevent pregnancy after sex and must be taken within 72-hours after unprotected sex or if your primary birth control failed. The sooner you take it, the better it will work. It is not meant to be used as a regular form of birth control because it is not as effective.

If you find that you are using Plan B frequently, talk to your doctor about finding a primary birth control method (a “Plan A” method) that is right for you.