Normal menstrual cycle is 21-35 days, an average of 28 days, a week in advance, push back, are within the normal range. Excessive mental tension, excessive anxiety, environmental changes, medication factors, menstrual fatigue, cold, stimulation and other factors can cause menstrual changes; hyperthyroidism, hypothyroidism, abnormal ovarian function, polycystic ovary syndrome, these factors will affect the menstrual situation. Now the menstruation has been delayed for a week, if there is a history of normal sexual life, first of all, to exclude whether there is a relationship with pregnancy, there is no factor of pregnancy, it is recommended that the best is to do an ultrasound, blood HCG, progesterone test, if the exclusion of pregnancy, then consider whether there are endocrine disorders caused by the factors.