Flat spot/indent?

Ka

Does this look like a flat spot on the top of my sons head? He does favor that side when he sleeps. I try to do as much tummy time/holding/switching positions with him as possible but that spot worries me. Its weird because its on the very top of his head. I'm going to bring it up at his appointment but it isnt until next week. Hes only 8 weeks old.