Delayed menstruation with blood may be due to pre-menstrual abortion, gynecological diseases, endocrine system diseases and other reasons. 1. Pre-eclampsia: After the last menstrual period, whether there has been conjugal intercourse to determine whether there is a possibility of pregnancy. When a woman is pregnant, she will stop menstruating, and if she has a pre-eclampsia, she will have vaginal bleeding that is less than the amount of her menstrual period. 2. Gynecological diseases: Cervicitis, endometrial cancer, cervical cancer, uterine fibroids and other gynecological diseases can lead to damage of blood vessels, which will lead to the symptoms of vaginal bleeding. 3. Endocrine system diseases: inappropriate use of contraceptive pills and other drugs, affecting the normal hormone level, which can lead to irregular vaginal bleeding. Patients with delayed menstruation with blood should go to the hospital in time in order to clarify the specific causes of the disease and treat the symptoms.