I get really bad hip and butt pains when I lay down. A pillow usually helps me a tiny bit. Just another annoying part of pregnancy. It may be worse for you though. If it gets to a point where it's making you cry, then I would call doctor, but it really isn't anything to worry for.
Thanks im trying to avoid the hospital :)
You could put a pillow in between your legs when you lay down. Or take Tylenol or both lol.