34 weeks pregnant & having right side rib pain, when i sit or lay down or walk or move it hurts! why is this?

Rib pain 34 wks: If you do not have a cough or cold or other respiratory infection, your rib pain may be caused by the growing uterus. AS the baby grows the uterus enlarges and pushes up against the muscles in your chest wall. All of the ligaments at the ends of the muscle relax a bit during pregnancy allowing the abdomen and chest to accommodate a growing baby. Check with your medical provider about this.