Inconsistent feedings

Is anyone else’s baby inconsistent with their feedings? Sometimes my son will take 4 ozs at 31/2 hours and other times he seems hungry after 2 hours, I will try everything else before feeding him early but when nothing else works I make him a bottle and he eats it like he’s never been fed. He’s very inconsistent with his eating and it drives me crazy. I’m not sure how he possibly could be hungry after 2 hours when he takes 4 ozs. Does anyone else have this problem? Is this normal?