Emergency contraception is birth control (something used to prevent pregnancy) that you use after you've had sex. You can use it if you have sex without birth control or if your birth control fails, such as when a condom breaks.
There are 2 main types of emergency contraception:
Medicines ("morning-after pills")
Getting a copper IUD (intrauterine device) inserted in your uterus
These methods are called "emergency" because you should be using another method to keep from getting pregnant. You shouldn't depend on doing something after you have sex.
Use emergency birth control as soon as you can after sex to avoid getting pregnant—the sooner you use it, the greater the chance it will work
You can get several different types of medicine that work as emergency contraception pills
Putting in a copper IUD is the most effective form of emergency birth control and will continue to prevent pregnancy for up to 10 years (or until you have it removed)
Pills are more commonly used as emergency birth control, but a copper IUD works better and provides ongoing birth control.
These are pills you take soon after sex to avoid getting pregnant.
There are several different kinds of morning-after pills:
Levonorgestrel must be taken within 3 days of sex—in the United States it's available over the counter (without a prescription) at pharmacies
Ulipristal acetate must be taken within 5 days of sex—you need a doctor's prescription to get it
Combination oral contraceptives (birth control pills), available with a doctor's prescription, can also be used but sometimes cause nausea and vomiting—you take 2 pills followed by another 2 pills 12 hours later
Levonorgestrel works better the sooner after sex you take it. It doesn't work as well in obese women.
A copper IUD is a small T-shaped plastic device wrapped in copper wire that is placed in your uterus (womb) to prevent pregnancy.
When used correctly, emergency birth control works for most women who use it.