There has never been a reason for women to abstain from sex during pregnancy except in rare cases where the doctor felt that the risks outweigh the benefits. This may include certain cases of preterm labor with advanced cervical dilation; preterm, premature rupture of membranes; or placenta or vasa previa. Also, women who have had a cervical cerclage during pregnancy should probably abstain. Otherwise, have fun!
Most women find sex during pregnancy more satisfying and pleasurable than outside of pregnancy. Sex during pregnancy is not associated with an increased risk of miscarriage, preterm labor, or any other complications of pregnancy. Even in cases where penetration may be recommended against, like the situations listed above, orgasms during pregnancy are still perfectly fine. If you have a cervical cerclage and don’t need penetration to orgasm, then stop reading this and get to work!