Grunting, squirming, and pulling his legs up

Sarah
So my little man doesn't sleep soundly anymore. He's 1 month old. He grunts and squirms around. He also pulls his legs up and doesn't like to stay on his back (he rolls to his side). He has normal bowel movements and his stool is soft so he's not constipated. Can anyone give me suggestions to what could be going on??