If the patient’s menstruation is usually very regular, and once in a while the menstruation is delayed for a month and has not yet come, there are two main possibilities to consider: first, the patient’s conception. After conception, the embryo develops in the uterine cavity, and the estrogen and progesterone levels in the patient’s body will be very high. So the patient will not appear again before menstruation, although the hormone level drops and the endometrium loses the support of high hormone level and peels and bleeds. So women who are sexually active must check the blood or urine HCG to determine if they are pregnant. If she is pregnant, further ultrasound will be done to observe whether the pregnancy is intrauterine or extrauterine. And according to the results of the examination, combined with the patient’s own fertility requirements, to determine the further diagnosis and treatment program. Secondly, consider that the patient may have occasional menstrual disorders. Excluding pregnancy, the patient’s menstruation is delayed for a month, the first thing to consider is that it is an episodic menstrual disorder. Episodic menstrual disorders are mainly related to seasonal changes, women’s emotional changes, increased stress, work and study, environmental changes and other external factors. Generally, the patient’s menstruation can be normalized in the next cycle and no special treatment is needed.