The morning-after pill is a high-dosage hormonal birth control pill that women take up to 72 hours after intercourse. Dependent upon where you are in your cycle, it’s designed to:
1) Prevent or delay ovulation (e.g. the release of an egg from your ovaries)
2) Interfere with the fertilization of an egg
3) Prevent implantation of a fertilized egg in the uterus by altering the uterine lining
Morning-after pills should not be used as regular birth control as their safety has not been tested. They are not approved by the FDA or recommended by the manufacturer for routine use.