An emergency contraceptive pill (ECP) is sometimes called “morning after” pill or postcoital contraceptive.
It is a backup option for contraceptive emergencies. It can help prevent an unintended pregnancy if taken as soon as possible within 72 hours (3 days) after unprotected sex or contraceptive failure has occurred. It is more effective the sooner after unprotected sex it is taken.
It is not a regular contraceptive method and is intended for “emergency use” only.
It is not an abortion-inducing pill. It does not work if a woman is already pregnant.
Reference: Family Planning: A Global Handbook for Providers, WHO
