The oral emergency contraceptive pill can be effective immediately after having sex without taking safety measures. It is generally recommended to be taken within 72 hours of intercourse to reduce the risk of unintended pregnancy and the earlier the pill is taken the better the results. Of course, the emergency contraceptive pill is not a 100% guarantee of absolute contraceptive success, and some people may experience contraceptive failure. In addition, the emergency contraceptive pill should only be used occasionally and is not recommended as a regular means of contraception. In general, the pill should not be taken more than three times in a year and not more than once a month. If you take too much, it may cause menstrual disorders and irregular vaginal bleeding in women, which may also have a greater impact on future pregnancies. Therefore, it is recommended that if you do not have a need to have children, you must do proper contraceptive measures before sex, such as wearing condoms throughout the contraception, or insist on taking short-acting oral contraceptives.