In the early stage of pregnancy, the embryo is still unstable. If you have sex at this time, orgasm will stimulate the uterus to contract, and the contraction of the uterus will lead to the detachment of the gestational sac from the uterine wall and the rupture of capillaries, so vaginal bleeding will occur. It is recommended to actively treat the fetus with bed rest and to do ultrasound examination to find out whether there is blood in the uterine cavity and to understand the development of the embryo. It is recommended to draw blood to check the blood HCG and progesterone to see if these indicators are normal, and then give the appropriate medication for antifetus until the clinical symptoms disappear. It is recommended not to have sexual intercourse during the first and second trimesters of pregnancy to avoid the possibility of preterm labor or miscarriage.