I'm a big fan of prenatal yoga, both for the stretching and the strengthening. I have a previous back injury, disc herniations in L4 and L5 in my lumbar region, and sciatica as a result. But I'm 18 weeks pregnant (and huge! lol) and so far, my back has really not bothered me much, knock on wood. I think it was worse before I got pregnant, so the yoga is helping a lot.
I have been having that same problem for about a month and a half now. Up until today all I was told is to use heating pad, hot showers/baths, massage, and of course tylenol. Yesterday was my 21 week mark and my doctor gave me a script for tylenol 3. It has codine in it and so far so good. You just have to wait until you get to a certain point in the pregnancy. Good luck!!
I have the same problem.... I had problems even before I got pregnant but now being pregnant, its even worse. I've noticed having my knee proped up while laying on my back/side helps. Other than that there's not much you can do.
I hope you don't have a doctor like I do. Mine told me all I could do was hope the baby moves off the nerve lol. There are some things you can try. I found that getting on my knees, laying my upper half down, and pushing on my lower belly helped move him off my nerve some. It didn't completely stop hurting, but I could move. I also read in a magazine that laying on your side (the one that's not hurting) can help. It didn't help much for me, but it may for you.