Menstruation is affected by a variety of reasons such as cold and flu, eating more cold, staying up late, stress, or taking certain drugs such as diet pills, may cause delayed menstruation. In the last cycle did not take effective contraceptive measures, does not exclude the possibility of pregnancy, as long as there is intercourse menstrual delay should first buy an early pregnancy test paper to check, to exclude the delayed menstruation is not caused by pregnancy, and do not need to do much treatment and then patiently wait a week to see. The first thing you need to do is to take drugs and communicate with your doctor in time so as not to affect your menstruation and cause emotional stress. If your menstruation is irregular for two or three consecutive months, it is advisable to have your blood examined in time to determine what causes it and treat it in time.