If the menstrual period comes for 10 days and the volume is relatively small, it is an abnormal phenomenon. The most common causes are as follows: 1. Endocrine disorder causing a longer period and a smaller amount. 2. Pregnancy. After someone is clinically pregnant, there will also be irregular vaginal bleeding, which can be mistaken for menstruation and ignore the pregnancy. It is recommended to go to the hospital to take blood test for blood HCG, if the blood HCG > 10mIU/mL is pregnant. 3. Endometrial lesions. If necessary, ultrasound examination can be done to understand the condition of the endometrium. If the endometrium has abnormal echogenicity or irregular echogenicity, it is recommended to do diagnostic scraping and send the scraped out tissues to pathology for laboratory tests for pathological diagnosis.