In the first trimester, your hormones fluctuate, and appetite and blood flow increase. unless you have an infection, here are a few reasons why sex in the first trimester might hurt your vagina is dry because of hormonal changes. During the first trimester, many women report no great desire for sex because they feel tired and nauseous, but during the second trimester, they are feeling better, there is more lubrication. having a sexually transmitted infection during pregnancy can cause serious health problems for you and your baby. Avoid all forms of sex vaginal, oral and anal if your partner has an active or recently diagnosed sexually transmitted infection. As there are many changes in the sex life during first trimester such as hormone fluctuate , blood flow increases and there can be increase of appetite of woman. During pregnancy hormones like estrogen and progesterone rises. If you still have any doubts or concerns about sex during pregnancy, discuss it with your doctor. Its also not unusual to feel overwhelmed by the physical and emotional changes youre going through. sometimes, you may ask yourself whether or not you can have sex with your partner during pregnancy. Many pregnant women think that having sex during pregnancy can lead to miscarriage. A miscarriage is a pregnancy loss that happens within the 20 weeks of gestation, i.