Take a warm bath and see if that helps. If not go see a chiropractor tomorrow because i know it really helps with my back pain. My step dad's a chiropractor and he adjusts me almost every week because my lower back is out of alignment due to the pregnancy. It's perfectly safe.
I'd take a painkiller and a nice bath for relief. X
You may also have a kidney stone. You may want to mention it to your OB.
I'm on baby #5 also, I have been in pain for almost a week now. The Dr told me she is sitting on my sciatic nerve.
Thanks everyone I will be sure to talk to my dr about all this... its just so painful at times
If it's not a kidney stone or anything like that, ask if you can go to a medical massage to help. I did that and PT to help me through my last pregnancy.