Emergency contraceptive pills should not be taken twice a month because they have a lot of side effects in clinical practice. The original purpose of the emergency contraceptive pill is to make up for the failure of contraception resulting in unwanted pregnancy, such as the use of condoms, resulting in condom dislodgement, or condom breakage, it is necessary to take emergency contraceptive pills to give the implementation of remedial measures. Taking two emergency contraceptive pills in a row within a month is likely to lead to more serious endocrine disruption, menstrual disorders or irregular vaginal bleeding. In addition, emergency contraceptive pills contain a large amount of high potency progesterone, sometimes may lead to liver and kidney function damage, so should not take emergency contraceptive pills twice in a month.