Your uterus is right above your pelvic bone. When I was preggo w/ my first son, I had lots of pain from streching uterus. I was about 8wks preggo, and it felt like massive AF cramping, all over that lower belly area. Just like meggs said. It was pretty painful for me, I couldn't walk, and it always hurt at night. Luckly it only lasted couple of weeks. If you have it, trust me, you'll know. let's hope you don't experience it.