9 week old eating alot more?

My son was 5lb 12oz when he left the hospital. Now at 9 weeks he’s 9lbs 8oz. He at 4oz at 6 4oz at 8 and probably could have ate more but I didn’t wanna overfeed him. He’s never ate this much. Does that mean I need to increase his feedings to 5-6 oz at a time or feed him every 2 hours now? He was crying so bad I thought his belly was hurting but then I saw his fist in his mouth (what he does when he’s hungry) I fed him 2 and he ate it so fast I gave him another 2 right away.