Before you take emergency contraceptive pills (ECPs), be sure you understand both the benefits and the possible problems of using ECPs. This fact page also lists the danger signs you should watch for. If you have any questions as you read, we will be happy to talk about them with you.
Emergency contraceptive pills (ECPs) are hormonal pills (similar to birth control pills) that you take to try to prevent pregnancy after you have unprotected vaginal intercourse (birth control method fails, no birth control method used).
ECPs may be combined estrogen/progesterone pills (such as PREVEN) or progesterone-only pills (such as PLAN B).
The pills either keep the ovary from releasing an egg, thicken cervical mucus or change the lining of the uterus in such a way that a fertilized egg may not attach and develop into a pregnancy.
The pills should be started preferably within 72 hours but up to 96 hours of unprotected vaginal intercourse. The sooner they are taken, the more effective in preventing pregnancy they will be.
These emergency pills prevent pregnancy about 76-99% of the time, depending on when, in the cycle, unprotected intercourse takes place. However, this method fails to prevent pregnancy in some cases, because:
- a fertilized egg has already implanted in the uterus
- too much time passed since unprotected vaginal intercourse
- failure of the drug itself
A sensitive urine pregnancy test should be done before taking ECPs if you think there is any chance that you could already be pregnant (last period was late, light, or short, or if you feel pregnant).
You should not use these pills if you are (or think you are) already pregnant. However, if you are pregnant, or if the pills fail and pregnancy occurs, there have not been any reports of serious side effects to the woman or to the fetus from taking the pills.
Some reactions to these pills (for about 24 hours) may include:
- nausea and/or vomiting
- breast tenderness
- irregular bleeding
- headache or dizziness
Your next period could be early or late, or could be lighter or heavier. If you use ECPs more than once in a monthly cycle, the chance of having problems with your next period will be even greater.
If you see a clinician for any reason before you get your next period, you should tell him/her that you have taken ECPs.
It is important to think of a more reliable form of ongoing birth control if you are at risk of unintended pregnancy. After using ECP, some women continue on birth control pills or use an IUD. Ask your clinician about your future birth control options.
Having unprotected sex may have put you at risk for sexually transmitted infections (STIs) and a serious infection could cause sterility. If you think you could be at risk for STIs, you should talk to your clinician about getting tested.
You should come back to the clinic four weeks after taking these pills for a checkup if you have not had a normal period, or if you feel like you could be pregnant, or if you have any early signs of pregnancy (such as feeling sick to your stomach, feeling very tired, breast swelling or tenderness).
To prevent feeling sick to your stomach or throwing up when you take the pills:
- do not take the pills on an empty stomach
- you can get something for nausea at the drugstore without a prescription (like Dramamine® or Bonamine®) to take about an hour before taking ECPs if you want to
- time taking the pills so that you take the second dose before going to bed, if you can
Call Women's Health Services if you:
- have questions;
- think you have a problem;
- are so sick to your stomach or are throwing up so much that you can't take the second dose of pills.
When the Student Health Center is closed, you can contact NYU Public Safety at 212-998-2222 if you experience any of the above symptoms or if you have any concern that can't wait until the Health Center reopens. NYU Public Safety will put you in contact with the NYU Medical Center Emergency Room.
Immediately go to an emergency room if you have any early pregnancy danger signs, such as:
- Possible Tubal (Ectopic) Pregnancy: Sudden pain, or pain that lasts, or strong cramps low in your abdomen, usually on one side or the other - with or without bleeding; fainting or dizziness that lasts more than a few seconds (could be a sign of bleeding inside your abdomen).
- Possible miscarriage: Heavy bleeding, sometimes with clots, pieces of tissue or bad cramps; a period that is heavy and longer; fever, or pain in your abdomen.