It is not allowed to have sex during the first and second trimester of pregnancy because it may cause miscarriage, premature birth, intrauterine infection, placental abruption, etc. Therefore, it is important to remember not to have sex during this period to avoid serious consequences. It is possible to have sex in the middle of pregnancy, and there are no consequences when the semen enters the vagina. The sperm enters the vagina and usually dies on its own in 2-3 days, because at this time the ovaries are no longer in cycle and the sperm enters the uterine cavity and does not unite with the egg, because there is no ovulation during pregnancy. So having intercourse in the middle of pregnancy, semen to the vagina will have no effect on the pregnant woman or the fetus. However, it is important to pay attention to the gentle action of sexual life, and it is also recommended that the frequency of sexual life should not be too frequent, so as not to stimulate frequent contractions of the uterus, causing intrauterine lack of oxygen to the fetus.