Emergency Contraception and Your Cycles
Emergency contraceptive pills like Plan B or iPill or ELLA are just a contraceptive pill with a very large dose of hormones. It works by trying to halt your cycles as soon as possible to prevent ovulation. When you do not ovulate, there is no egg to fertilize and you can’t get pregnant.
After about 7 days, the hormones will be totally gone from your body and your body must restart your natural cycles. There is no predictable or fixed way in which this will happen. It may happen immediately, or it may take a few days or even weeks. Most often, it will delay your next menstruation for a few days or a few weeks. Your new cycles may even be different in regularity and length.
One of the most common side effects of taking an emergency contraceptive is withdrawal bleeding. This is like a period, but it is not menstruation. It is artificially caused by the large dose of hormones leaving your body. It is exactly the same as a woman on normal birth control pills get when she gets to the week without hormones (her period week). It happens between 5 and 7 days after taking the pills. If you do not get withdrawal bleeding, it does not follow that you are pregnant. Most do, some don’t.
If you are close to your menstruation or are already menstruating, it will likely stop it within a few hours or a day, or it will not start, because of the large dose of hormones and what it does to your cycle.
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