There are several different reasons for not coming to menstruation for one week: First, it may be a normal physiological symptom. Women may have problems such as delaying menstruation in advance during the onset of menstruation. Generally, it is normal to advance or postpone menstruation for 3-7 days, and treatment is unnecessary; Second, consider irregular menstruation. If this happens frequently, consider that it is caused by endocrine disorders, mental stress or environmental changes, or it may be caused by overwork and delayed menstruation; 3. If you have had unprotected sex before menstruation, menstruation delay may be a symptom of pregnancy, and you need to go to the hospital in time to check whether there is pregnancy; Fourth, if there are gynecological diseases or systemic diseases, they may also affect the normal menstrual cycle, and the symptoms of delayed menstruation may occur.