A: Babies move a lot during pregnancy, especially during the second trimester, where you are now. At times, they will press on certain nerves that can cause a great deal of discomfort. When babies kick a lot, they can also cause part of the uterus to tighten (a Braxton Hicks or false contraction). Many women experience Braxton Hicks contractions at an early point in pregnancy, particularly in a second or third pregnancy. These feel like your whole belly is getting tight and hard, but it normally doesn't hurt. If you are having painful uterine cramps, no matter how far along in pregnancy you are, call your practitioner to let her decide if you need to be seen.