Sexual intercourse is allowed during the 3rd to 6th months of pregnancy. In the first 3 months of pregnancy, the embryo is not very stable, so sex can easily stimulate the uterus to contract and cause miscarriage, especially when there are symptoms of pre-eclampsia or habitual miscarriage. The rest of the time you can have sex, you should pay attention to gentle movements when having sex, avoid rough and violent movements. If you have abdominal pain or vaginal bleeding after sex, you need to take rest and seek medical attention.