A little blood a few days before the period may be a normal physiological phenomenon of early menstruation, but also may be caused by vaginitis, cervical polyps and other diseases, as well as other diseases such as vaginal polyps. 1. Physiological phenomenon: women may have the phenomenon of early menstruation, usually a week or so in advance of menstruation is a normal physiological manifestation, so the patient will have the symptoms of a little blood in the first few days of menstruation. 2. Endometrial polyp: endometrial polyp is considered to be caused by high estrogen level and inflammation stimulation, patients will have abnormal uterine bleeding, excessive menstruation, irregular menstruation and other manifestations, which leads to the symptoms of a little bit of blood a few days before the menstrual period. 3. Cervical polyps: Cervical polyps are caused by inflammation and infection, and patients will have abnormal vaginal bleeding, increased menstrual flow, and bleeding during sexual intercourse, leading to the symptom of a little bit of blood a few days before the menstrual period. 4. Other: Vaginal polyps, uterine fibroids, cervical cancer and other diseases can also cause patients to have a little blood a few days before the period. When the patient has a bit of blood a few days before the period, it may be caused by physiological factors and does not need to be treated. If it is caused by a disease, it is recommended to consult a doctor in time to avoid delaying the condition.