The sudden onset of vaginal bleeding on the 12th day after an abortion is often related to the following factors. The first is bleeding caused by endometrial inflammation due to infection by pathogenic bacteria in the uterus, which is often accompanied by pain in the lower abdomen and an increase in vaginal discharge before the vaginal bleeding starts. The second is caused by eating certain foods, such as over-nourishing the body with large amounts of ginseng or deer antler, which can also lead to vaginal bleeding on the 12th day of menstruation. The third one, due to not having a good rest after the operation and being more tired, can also lead to vaginal bleeding. Therefore, it is best to go to the hospital to do the appropriate examination, and according to the results of the examination, the clinical treatment will be given in time.