Anyone ever had this before?

Did a bunch of walking today. Around 4 hours worth. Came home and DTD with my SO. Ever since I have been having this horrible pain in my pelvis and upper/ inner thighs to the point that I can not walk with out being in excruciating pain. When I am lying down I am fine. Only when I move or go to stand up. Even sitting hurts. Had an appointment with my OB today, Dr didn't check me today, but last week was 1cm dilated. Baby's movements have been fine. Is this something I should be concerned about? Has anyone else experienced this?