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Emergency Birth Control

What is emergency birth control?

Emergency birth control, also called the morning-after pill, is a medicine that can prevent pregnancy if a woman takes it within 72 hours of having intercourse. It may be used when you have had unprotected intercourse (no birth control used) or have been sexually assaulted (raped). It may also be used when a barrier method of birth control has failed (for example, a condom breaks). The emergency birth control does not cause an abortion. The pill works by hormonally or mechanically causes changes in the lining of the uterus that prevent implantation of a fertilized egg, prevent or delay ovulation (release of an egg from the ovary), or interferes with movement of the egg or sperm through the fallopian tube to the uterus.

If the emergency birth control pills fail to prevent pregnancy, or you are already pregnant when you take them, there is no evidence that the pills will harm you or the baby. The pills will not end a pregnancy if a fertilized egg has already implanted in the uterus.

When is it used?

The "morning-after pill" is a 2 dose pill pack. You take the first pill within 72 hours (3 days) of unprotected sexual intercourse, sexual assault, or condom/diaphragm failure. You then take the second pill 12 hours later. The pills may cause nausea and vomiting.

What are the benefits of emergency birth control?

The benefits are:

  • preventing an unplanned pregnant
  • preventing an abortion for unwanted pregnancies
  • reducing the costs of abortions and miscarriages
  • reducing the complications of pregnancies, delivery, abortion, or miscarriage

Who should not use emergency birth control?

You should not use emergency birth control if:

  • You know or suspect that you were already pregnant before you had unprotected sexual intercourse.
  • You are allergic to birth control pills.
  • You have abnormal vaginal bleeding.

If you have had blood clots from previous use of birth control pills, or if you have had certain other health problems, it may be safer to take pills that do not contain estrogen.


When should I call the office?

You should call the office within 24 hours after you have had unprotected sexual intercourse. The sooner you start taking the emergency birth control pills, the better your chances are of preventing pregnancy. Also call if your menstrual period does not start within 21 days of taking the emergency birth control.

If you have taken emergency birth control pills, call the office right away if:

  • You have pain, redness, or swelling in your leg.
  • Your arms, legs, hands, or feet are numb.
  • Vision problems, such as blurred vision or a partial or total loss of vision.

It is common to have breast tenderness after taking emergency birth control. The tenderness usually goes away in a few days and is not a medical problem.