When a woman is pregnant for 40 days and sees red, it is called abnormal vaginal bleeding. There are two possibilities to consider: firstly, due to insufficient corpus luteum function in the body, resulting in low levels of progesterone and causing preeclampsia. Second, due to the fertilized egg did not land in the uterine cavity, but in the fallopian tube local bed, fallopian tube due to the poor environment at the same time the lumen is narrow, then with the growth and development of the fertilized egg can cause local abortion, or lead to the fallopian tube rupture caused by irregular vaginal bleeding, it is recommended that as soon as possible to go to the gynecology department of the hospital to check the color ultrasound, and also to check the blood HCG and progesterone to diagnose the specific cause.