The reasons for not having a period for a month can be divided into two conditions, one is pregnancy and the other is menstrual disorder. If your period is delayed, you can go to the hospital for an HCG test and an ultrasound of the abdomen to find out if you are pregnant. If you are not pregnant, you should find out what are the causes of menstrual disorders. Sometimes menstrual disorders are closely related to common polycystic ovary syndrome and premature ovarian failure, etc. Only when you find the cause of amenorrhea, you can adopt the principle of symptomatic treatment. A woman’s mood, mental state, work status, external environment, diet and living can also cause menstrual disorders.