Slight bleeding on the 40th day of pregnancy may be caused by physiological reasons or pathological reasons such as biochemical pregnancy or preeclampsia.
1. Physiological reasons: in about 40 days of pregnancy, the embryo will be implanted, which will stimulate the uterus to bleed slightly, but the amount of blood in this case is small, and usually bleed for about a day, which is a normal phenomenon of pregnancy.
2. Pathological causes: generally pathological causes of bleeding may be biochemical pregnancy, preeclampsia, abortion, ectopic pregnancy, fetal arrest and so on. Bleeding caused by this reason is usually larger, even more than the amount of menstruation, or accompanied by irregular abdominal distension and pain.
In general, any bleeding during pregnancy should go to the hospital in time, under the guidance of the doctor to further clarify the examination and appropriate treatment.