Within 72 hours of unprotected sex or contraceptive failure, the earlier the pill is taken, the more effective it is in preventing pregnancy. 2 tablets should be taken orally in a single dose; or 1 tablet should be taken for the first time and the second one 12 hours apart. After taking the pill, women may see changes in their menstruation, mostly in the form of early or late menstruation in the month of taking the pill. However, the 72-hour emergency contraceptive pill cannot be used as a regular contraceptive method and can only be used once in a month. If women use it frequently, it may cause menstrual disorders, and in serious cases, it may cause infertility. In addition, if a woman is one week overdue for her period, she may be pregnant and a pregnancy test should be performed. If irregular vaginal bleeding occurs along with abdominal pain, prompt medical attention is needed to rule out ectopic pregnancy.