I had this with my first pregnancy but I didn't start getting the hip pain and popping until the 3rd trimester. With this one, at 16 wks today, I have been having some hip problems already for a few weeks. I have been told it's due to the relaxant your body releases when you are pregnant to loosen the bones to allow the baby to fit through the canal at delivery time. I hated it the first time around and I don't suspect I'll like it much better this time! I noticed it the most when I was in bed and I would shift my weight to turn on my back and then to the other size. Snap, pop!!! Owwwww.