Incredible Back Pain

Lisa

I'm 37 weeks and 3 days. It seems whenever I try to sleep is when I get the absolute worst lower back pain. I have a pregnancy pillow I coil and put between my legs and that helps some. Last night was particularly bad. Now I'm awake with the same pain hoping that sitting on a heating pad will help, but the pain is pretty intense still. Any ideas why and what to do to help?