How does emergency contreception work?

Emergency contraception (EC) works primarily by preventing or delaying ovulation, which means it stops the release of an egg from the ovaries. Depending on the type of EC used, it may also alter the uterine lining to prevent a fertilized egg from implanting. EC is most effective when taken as soon as possible after unprotected intercourse, ideally within 72 to 120 hours, depending on the specific method used. It's important to note that EC does not terminate an existing pregnancy.