Possible flat spot on the back of baby’s head?

So I feel like my baby girl has a flat spot on the back of her head. She is in her swing a lot but she does also do tummy time and she is carried a lot when we go see family or they come to us which is a lot. At her four month check up the doctor didn’t really look when I mentioned it and just said to do tummy and other activities to help with flat spots. I don’t know really what to do if I should make another appointment and ask him to check it out? Or go see another pediatrician? I would really like to fix this before it’s to late and she has the flat spot forever. Any other moms experience this ?