The main way that Plan B works is by delaying ovulation (the monthly release of an egg). Therefore, if the intercourse occurred shortly after you ovulated, Plan B may not work as well for you. However, Plan B may also interfere with fertilization (the union of sperm and egg) and implantation (when the fertilized egg implants itself into the uterine lining). According to the manufacturer, the treatment prevents seven of eight pregnancies that otherwise would have occurred, making it about 87% effective.
One of the most common side effects of Plan B use is menstrual irregularity. Therefore, your next period could be earlier than usual, later than usual, or spotty (meaning you may bleed for a few days, stop, and then bleed some more). However, if you are a week or more late for your period, take a pregnancy test. If it is negative, repeat the test every two weeks until you have a normal period or a positive test result.
Plan B should not be used as a regular method of birth control as it is less effective than other methods. If you are going to continue to have sexual contact, you may want to think about using a regular form of birth control. If you live near one of our offices, please call us for an appointment to discuss your contraceptive options. If you live further away, contact the Family Planning or Planned Parenthood office closest to you.
9. May 2012
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