After taking the pill and then intercourse may be pregnant, the emergency contraceptive pill belongs to the hindsight contraceptive pill, that is, the emergency contraceptive pill only to use the pill before intercourse to play a contraceptive effect, after intercourse within 72 hours of taking the emergency contraceptive pill will have a contraceptive effect, if it is to take the emergency contraceptive pill in advance, is no contraceptive effect. If you take the pill and then have intercourse, in order to ensure that the contraceptive effect, you need to take the pill again, but the pill will affect the endocrine, may affect the normal cycle of menstruation, may also lead to irregular vaginal bleeding, can not be more than three times a year oral. In addition to affecting the menstrual cycle, long-term use of the pill may also cause breast or cervical malignant tumors, which may lead to breast cancer or cervical cancer, so you can’t take emergency contraceptive pills as a common contraceptive measure.