Emergency contraception is a method used to prevent pregnancy after unprotected sex or contraceptive failure, such as a broken condom. It is most effective when taken as soon as possible, ideally within 72 to 120 hours after the incident, depending on the type used. There are different forms of emergency contraception, including pills containing hormones like levonorgestrel or ulipristal acetate, and the copper intrauterine device (IUD). These methods work by delaying ovulation, preventing fertilization, or stopping a fertilized egg from implanting in the uterus.