I am 34, and 38 weeks pregnant. I know what back pain is like, I have chronic back pain and have had a microdiscectomy L5-S1 in 2007. I have had a sensation but it has increased in the past 2 weeks. The sensation starts in my lower back and moves up to my head, then finishes in my chest. It feels like a pulsating electrical charge that is quite painful and stops me in my tracts. It goes away if I change my position. It feels like an adernaline rush up my spine. Im not thinking it labor pains, because it is not radiating to my tummy. I can t try and have orgasim because it causes the sensation. It is quite paralysing. I have a doctors appointment monday, but I worried because it is happened quite often if I get into the wrong position.