Third trimester, shooting pain up and down back/spine

Is anyone else experiencing this? Currently 37 weeks, it started at 35 weeks I sometimes get a shooting pain that will either start in my lower back or in the back of my neck and travel up and down my spine/back when I sit or lie down. Sometimes it's really painful and I feel damn near paralyzed when it occurs so I shift my position and it will go away. I asked my OB about it but she isn't sure what it is since it occurs throughout my back and she doubts it's pregnancy related. I think it is because I've never experienced it before. Anyone experience the same thing?