But for some, the sensitivity can make interactions painful. An hour or two of mild cramps isn't unusual because both orgasm and the prostaglandins in semen can cause uterine contractions. Still, the body changes that come with Pregnancy and sex can also turn familiar territory into terra incognita. There may be an alternative that's far more gentle and patient with your skin barrier. With ever-shifting hormones and getting used to a new body, there are many changes that can complicate desire. If you've had preterm labor or birth in a previous pregnancy or if you're at risk for Pregnancy and sex labor with your current pregnancy, your ob may restrict sex. Oral sex is okay too.