Delayed menstruation for more than 20 days may be related to pregnancy, endocrine diseases and other reasons, it is recommended to pay attention to timely. 1. Pregnancy: If a woman’s menstrual cycle is usually regular and she has recently delayed her menstruation for a longer period of time and has had sex, it may indicate the presence of pregnancy in her body. 2. Endocrine diseases: If there are endocrine disorders such as polycystic ovary syndrome and hyperprolactinemia, delayed menstruation may also occur, and in severe cases, it may affect daily life. There may be other reasons for delayed menstruation for more than 20 days, so it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy.