Girls, hello!) I'm writing for the first time, but I don't know where …

Girls, hello!) I'm writing for the first time, but I don't know where to go anymore. My son will be six months old soon, the baby is very plump, almost 10 kilograms? He hasn't turned over yet, he lies on his belly little, he doesn't like to turn from birth, despite all my efforts. He rolls from side to side very skillfully, but he doesn't turn over to his belly and there is no direct support on the handles. We were diagnosed with hypertrophia and delayed motor development. I'm very worried. We went through a massage course in 3 months, we plan to start swimming this month. We do charging constantly, exercises for turning over