If you have intercourse when you are newly pregnant and it does not cause pain in the lower abdomen or vaginal bleeding, there is nothing to worry about in this case. It is recommended not to have sexual intercourse during the first trimester, because if you have sexual intercourse and become sexually excited by orgasm, it can cause contractions of the uterus. The contraction of the uterus will cause the gestational sac to detach from the uterine wall, resulting in vaginal bleeding, pain in the lower abdomen, and other cases of pre-eclampsia, which may lead to miscarriage in severe cases. Also, intercourse is not allowed in the second trimester, also because the stimulation of intercourse can cause uterine contractions. In addition, the uterus is sensitive during the second trimester, so if there is external stimulation, it will cause contractions that may result in premature delivery.