Hips pain

C.

I'm 17 weeks now and lately I tried to avoid rolling on my back during sleep so I only sleep on my sides. Couple of nights before my hips started to hurt on both sides. Could they be already expanding at such an early stage or is it just the fact that I'm pretty thin and don't have much fat on my hips so the bones are pretty exposed? I don't feel anything on my clothes getting tighter or anything, it just hurts when I sit on them for a long time