Emergency contraception can be used when, for example, a condom breaks, after a sexual assault, or any time when unprotected sexual intercourse occurs.

The morning-after pill (emergency contraception) is a safe and effective way to prevent pregnancy after unprotected intercourse. It can be started up to five days (120 hours) after unprotected intercourse.

You may want to use emergency contraception if:

  • The condom broke or slipped off, and he ejaculated in your vagina.
  • You forgot to take your birth control pills, insert your ring, or apply your patch.
  • Your diaphragm or cap slipped out of place, and he ejaculated inside your vagina.
  • You miscalculated your "safe" days.
  • He didn't pull out in time.
  • You weren't using any birth control.
  • You were forced to have unprotected vaginal sex, or were raped.

Emergency contraception is also known as the morning-after pill, emergency birth control, backup birth control, and by the brand names Plan B One-Step, ella, and Next Choice.
Many people call emergency contraception the "morning-after pill." But that name is a little confusing. You can use emergency contraception up to five days after unprotected intercourse — not just the "morning after."

Emergency contraceptives are not as effective as any ongoing contraceptive method such as the pill or an IUD, and they should not be used as the only protection against pregnancy if you are sexually active or planning to be.

Emergency contraceptives do not protect against sexually transmitted infections.
In the U.S. there are two types of emergency contraceptives: The emergency contraceptive pills (morning-after pills) and the Copper-T IUD.

How Does the Morning-After Pill (Emergency Contraception) Work?
Emergency contraception is made of one of the hormones found in birth control pills — progestin. Hormones are chemicals made in our bodies. They control how different parts of the body work.

The hormone in the morning-after pill works by keeping a woman's ovaries from releasing eggs — ovulation. Pregnancy cannot happen if there is no egg to join with sperm. The hormone in the morning-after pill also prevents pregnancy by thickening a woman's cervical mucus. The mucus blocks sperm and keeps it from joining with an egg.

The hormone also thins the lining of the uterus. In theory, this could prevent pregnancy by keeping a fertilized egg from attaching to the uterus.

You might have also heard that the morning-after pill causes an abortion. But that's not true. The morning-after pill is not the abortion pill. Emergency contraception is birth control, not abortion.

A ParaGard IUD can also be used as backup birth control if inserted within 120 hours — five days — after unprotected intercourse. It is 99.9 percent effective. Talk with your health care provider if you're interested in getting an IUD.