Plan B helps prevent pregnancy by delaying ovulation. It can delay ovulation by about 3-4 days, thus allowing time for the sperm to die off and come out of the vagina. (Sperm can live up to 3 days inside the vagina).
Typically, during a period is when a woman has the least likely risk of pregnancy. However, this can depend on the length of her cycles. If a woman has very short cycles (less than 21 days between periods), then she could possibly ovulate during the time of bleeding. Most women have cycles that are normal, with periods occurring about every 26-28 days. In those women, the chance of pregnancy during a period is low, so Plan B would not prevent pregnancy.
Plan B is relatively safe for everyone. If taking it would make you and your partner feel less anxious, there would be no harm in taking it. Your partner may notice that her next period comes a little earlier or later than usual. It may be a little spottier or heavier than usual. Plan B is not a long term method of birth control.
Keep in mind, condoms, when used correctly & consistently, can be very effective at preventing pregnancy.
22. January 2012
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