7 month old’s head shape

Since my son was born, I always thought his head looked weird. I would compare it to others online to see if his head matched others who had craniosynostosis but was told by the pediatrician that it was mostly likely just positional plagiocephaly. His head is still flat on the right side, not as much now, but still flat. Well, at his 6 month appointment, we found out that his head hadn’t grown since his 4 month appointment. The doctor remeasured it a few times just to be sure, but since it was in the range for his age, they aren’t worried. But I am now. His head always was on the bigger side. I don’t know what to do. I wish I could post a picture on here. His forehead isn’t bossing or anything like that, but his head has like a bump in the front. It’s been like that since birth. I don’t know what to do.