Hip and pelvis pain while sleeping

I'm 16 weeks and having a hard time sleeping due to hip and pelvis pain in certain positions. I've read somewhere that starting in the 2nd trimester it's best NOT to sleep on my back. And honestly I've never been a back sleeper, but that's about the only comfortable position right now. The pain I'm having just shows up when I'm in a side position or I move too quickly. Is it really bad to sleep on my back yet? Or what other suggestions do you guys have to help with this?