You don’t need to use contraception during pregnancy because women usually don’t ovulate during pregnancy, and even if you do, you won’t get pregnant again. The reason is that after pregnancy the ovaries become dormant and do not secrete estrogen and progesterone cyclically, and the ovaries do not produce eggs anymore. At the same time, the uterine lining will no longer show cyclic changes and shedding bleeding, which can not provide a suitable environment for the egg to settle, so sexual intercourse during pregnancy can be clinically non-contraceptive. Mid-pregnancy can be appropriate according to the physical condition of the pregnant woman to have sex, but pay attention to the frequency as well as action is not too violent, but also need to pay attention to personal hygiene, to prevent the phenomenon of infection. After pregnancy coitus does not need contraception, but early pregnancy and late pregnancy is not recommended coitus, so as not to cause contractions caused by strenuous exercise, resulting in miscarriage, premature birth.