My daughter had a flat spot on one side of her head and she was born via C/S. She used to favour one side when she lay on her back, and no matter what we did to persuade her to turn her head the other way, she didn't.
Talking to other Mums at the time, I knew there were quite a few bubs who had misshapen heads too. There are little things you can do if it's caused by lying in the same position - the pediatrician will give you some tips (eg place something he likes to look at on the opposite side of where he usually looks so he has to turn his head the other way to see it).
Some babies need intervention to help their skulls reform into the "correct" shape. This is usually in the form of a helmet. Some of the Mums on this site have bubs who are currently wearing helmets. This seems to be the course of action in a relatively few amount of cases.
It's good you don't have long to wait to get it checked out (more for your sake than his). BTW Gabrielle didn't have to have a helmet fitted, and by the time she was one her head was back in shape.
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