A delay in menstruation for more than 10 days can be caused by a number of reasons. First of all, when there is an endocrine hormone disorder, polycystic ovaries or hyperprolactinism, there may be a longer delay in menstruation. Secondly, if you have unprotected intercourse during the month, you may not get your period because you are pregnant. Again, if there is stress, work pressure, late nights, or changes in eating habits, there may be a delay of 10 days. Generally, a delay of 7-10 days is normal and more than 10 days is abnormal. It is recommended to go to the gynecology department for blood tests, endocrine hormones including ultrasound. To determine whether there is any abnormality in the endometrial attachments, and also to rule out any abnormality in the endocrine hormone break. According to the situation, you can take certain oral menstruation drugs to promote menstruation in an appropriate amount.