It happens...: Emergency contraception pills (such as Plan B and other brands) can alter the menstrual for the cycle in which Plan B was taken, and sometimes the next cycle too. One should be sure to check a home pregnancy test about 3 weeks after sex, because Plan B works most of the time, but not all the time. Also, be sure to start using a reliable form of birth control, so that one will not need Plan B.
Answered 2/25/2015
3.2k views
2 doctors weighed in across 2 answers
2 doctors weighed in across 2 answers
90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more.
Ask your question