It's safe to take Plan B as many times as you need to prevent pregnancy after unprotected sex. However, you might choose a regular form of birth control.

Plan B One-Step, also known as the morning-after pill, is an oral medication and is most effective within 72 hours of having sex without birth control. Here, we discuss the best places to get this ...

Morning-after pills such as Plan B One-Step can lower a woman's chances of getting pregnant by 75-89% if taken within three days of having unprotected sex, according to Planned Parenthood.