Emergency contraception is used in a situation where a woman has had unprotected intercourse. It is 80-90% effective if used within 72 hours after unprotected sex. Emergency contraception is also called “the morning after pill” and the most common brand in the US is Plan B. Emergency contraception is a typically single dose of the progesterone levonorgestrel. The sooner it is used after unprotected intercourse the more likely it will work to avoid pregnancy.
Emergency contraception is typically packaged as either a single dose of levonorgestrel or two pills to be taken 12 hours apart. Studies have shown that either way of taking the medication is effective. I recommend taking the entire dose all at once even if it is packaged as two separate pills. This avoids the problem of remembering to take the second pill and is just as likely to work.
Emergency contraception should be taken within 72 hours after unprotected sex. The sooner after the unprotected sex the more likely it is to inhibit ovulation and therefore stop pregnancy. For this reason, some people keep emergency contraception available just in case there is a mistake. This allows for the morning after pill to be taken sooner after the event. This is also the reason Plan B is available in the US without a prescription. If you need emergency contraception you do not need to see a doctor first.You can simply buy Plan B at the pharmacy over-the-counter. I recommend also buying a pregnancy test. Do the pregnancy test prior to taking the medication to be sure you are not already pregnant. Although emergency contraception is most beneficial in the first 72 hours, there is some potential benefit even 5 days after unprotected sex. The failure rate is much higher after 3 days but there is still some chance that it will work between 3 and 5 days after unprotected sex.
One of the common misconceptions about emergency contraception is that it causes an abortion; it does not. The morning after pill works by blocking the ovary from making an egg; it inhibits ovulation. If there is no egg, there will be no pregnancy. This is why the timing is so important. The sooner the ovary is inhibited the less chance there will be an egg to get fertilized. There does exist an “abortion pill”, Plan B is not the same thing.
It can take up to 2 weeks for a pregnancy test to become positive after conception. I recommend taking a pregnancy test 2 weeks after using emergency contraception to make sure that it worked. If the emergency contraception failed to block ovulation and you are pregnant, the medication from the morning after pill will not cause birth defects. If you decide to carry the pregnancy, you do not need to worry about problems with the baby or the pregnancy because of the medication in the morning after pill.
The most common side effect from emergency contraception is to make your next period abnormal. It is hard to predict how your next period will be. It could be early, late, long, short, heavy, or spotty. It will very likely be different than what you are used to. Other side effects include nausea, dizziness, and headache. These side effects are less likely to occur and tend to be mild. If you have vomiting and throw up the medication, try retaking it but separate the dose by taking half now and the other half in 12 hours.
Emergency contraception is called “Plan B” for a reason, it should never be your plan A. The morning after pill has a much higher failure rate then any of the traditional contraceptives. Plan B has a contraceptive benefit of 80-90%, compare this to birth control pills at 98% or the IUD and implant at greater then 99%. If you find yourself needing Plan B you should really think about how you got into that situation. Your “plan A” did not work, is it time for a new plan A? I recommend making an appointment with your doctor to review birth control options to discuss what birth control might work best for you. One thing is for sure, if you continue to rely on emergency contraception, you will eventually have an unintended pregnancy. Use this as an opportunity to refine your birth control choice to something that will be less likely to fail.