Aunt i.e. menstruation, menstruation delayed and not pregnant may appear menstrual disorders, may be related to psychological factors, drug factors, lifestyle habits, diseases and so on. 1. Psychological factors: If you have too much pressure from study and work, irritable mood, depression, late night, etc., it may lead to delayed menstruation. 2. Drugs: If you are taking drugs recently, such as psychotropic drugs such as lithium carbonate, hormonal drugs such as progesterone, etc., it may affect the ovarian function, resulting in delayed menstruation. 3. Lifestyle habits: If you have bad lifestyle habits, such as staying up late or overworking, it may also lead to delayed menstruation. 4. Diseases: If you have abnormal thyroid function, polycystic ovary syndrome, hyperprolactinemia and other diseases, it may also affect menstruation. If a woman often has delayed menstruation and is not pregnant, she should seek medical examination and treatment.