Emergency contraception can prevent pregnancy after you've had sex without birth control or after your birth control method has failed—say, the condom broke or slipped off, your diaphragm got knocked out of place, or you forgot to take your birth control pills.
emergency
/i-ˈmər-jən(t)-sē/
noun
an unforeseen combination of circumstances or the resulting state that calls for immediate action
an urgent need for assistance or relief
noun
a brake (as on an automobile) that can be used for stopping in the event of failure of the main brakes and to keep the vehicle from rolling when parked
noun
drugs (such as the morning-after pill) or devices (such as an IUD) that are used to prevent fertilization or delay or prevent ovulation following unprotected sexual intercourse or contraceptive failure