The normal menstrual cycle is 21-35 days and the period is 3-7 days. It is within the normal range for menstruation to be 7 days early or late. Since the hormone levels in the body are not in a fixed state and may fluctuate and change to a small extent, the time of menstruation is not completely fixed. Normally, the menstrual cycle is 21-35 days, with an average of 28 days, and it is within the normal range for menstruation to be 7 days early or late. If the menstrual cycle is delayed for more than 7 days, pregnancy, gynecological diseases, menstrual irregularities and other possibilities should be suspected. It is recommended that patients go to the hospital for gynecological routine, ultrasound, sex hormone six and other related examinations to clarify the diagnosis and then properly regulate menstruation. In addition, long-term work pressure, mental stress or fatigue, irregular diet can also lead to irregular menstruation, patients are advised to pay attention to rest, avoid staying up late, and eat a regular diet, which will help menstruation to come normally.