plan b how does it work

Plan B works by temporarily delaying ovulation , which means it stops or delays the release of an egg from the ovary so that there is no egg available for sperm to fertilize. Without fertilization, pregnancy cannot occur. It is an emergency contraceptive taken after unprotected sex or contraceptive failure and is most effective when taken as soon as possible within 72 hours. Plan B does not cause an abortion and will not affect an existing pregnancy. It contains the hormone levonorgestrel, a synthetic form of progesterone, and its effect is temporary with no impact on future fertility.