There are two reasons for the sudden postponement of menstruation: First, if you have had intercourse without measures recently and your menstruation is delayed for more than a week, the possibility of pregnancy is relatively high, so you can consider doing a urine HCG or blood HCG test to make a clear diagnosis. Secondly, if pregnancy is excluded and the period is delayed for more than one week, it is considered to be menstrual disorder. Most of the menstrual disorders are related to the change of endocrine hormone level. Changes in endocrine hormone levels are related to various factors, including recent fatigue, late nights, decreased resistance, environmental changes, emotional changes, changes in diet, stressful life and climate changes. This can affect the endocrine hormone levels and lead to changes in menstruation. You can go to the hospital for routine gynecological examination and pelvic ultrasound, and take medication to regulate menstruation. Consider having a comprehensive analysis of the six female sex hormone indicators during menstruation. You should pay attention to rest, avoid straining and staying up late, relax, reduce stress and avoid too much emotional fluctuation as much as possible, so that the hormone level in the body is in a relatively stable state and the menstrual cycle is relatively stable.