All I know is for me, I always feel uncomfortable in the ribs cause that's where my son liked to push his feet against! I had a pregnancy pillow that I folded in half to "double up" in between my legs to keep them very apart while sleeping. Honestly, by 30 weeks I had trouble sleeping until he was born at 37 weeks! But all that discomfort will go away after the baby is born I promise! First night home I was able to sleep so well (in between the feedings at least) 😝