Went to my OB yesterday and he checked my cervix. I was 4 centimeters dilated and 100% effaced. He then went to swipe my membranes but there was nothing left for him to get. At around 2 this morning i started getting this horrible stabbing pain in my back and pelvis and my stomach got really hard. This lasted til around 5 and stopped. And has happened a few more times. Could this be early labor?