Should I be worried

I have always been concerned about my sons head it’s not flat but I feel like it’s not how it’s supposed to be either. He doesn’t have a perfect head from the back. The doctor did mention his head as well. Around 4 MO I did my best to keep avoiding his flat head. On his 6MO appt I asked him about his head he said I shouldn’t worry it was okay. But I do cause his head it’s a tiny flat he doesn’t have that shape his back head should have and I hate it 😖. His now 7MO should I ask a different doctor or ?