My last was a posterior baby. I had the lower back pain, more like a screwdriver being jammed right in my tail bone. It was fairly consistent and the ONLY thing that made me feel better was sitting on a birthing ball (gym ball) and rocking around and DH massaging my lower back. I tried on all 4s but having been awake for 23hrs I was too tired to do that for too long.

G'luck!