Doctor said my baby is big

I am 22 weeks and my doctor said my baby was larger than the average baby that far along. He said the baby is healthy but that he wants to do another ultrasound. Baby measures 9 days ahead. I think he is worried that my baby is going to get too big. He also said that I am gaining too much weight. I was 126 prepregnancy and now I’m 146. But he said it wasnt too big of a concern because of the size of the baby. Did anyone else get told they have a big baby and were still able to deliver vaginally? I am worried about having to have a csection if he’s too big. Will he slow down with his growth? My husband is very tall, so I think that’s why my baby is big.