My 3 month old favors his right side when sleeping. I've tried to turn his head and encourage him to lay with his head on his left side but even if he falls asleep that way he ends up back on the right side. At about what age will a Dr. Determine that it's not something he'll grow out of and that he'll need a hemlet? He has a full month before his next check up should I maybe go in before? The flat spot is pretty noticeable.