How much are your babies eating?

My son is a month old on Friday (was 4 weeks yesterday). He TYPICALLY eats like 3-4oz at a time.. but tonight he legit just ate 8oz in one sitting. He’s breastfed but we do bottles at night so dad can feed him. He even pace fed him! He stopped often to burp and to just generally pause. And even stopped for a decent period to heat up more milk. What’s crazy is that he is still making motions as if he’s still hungry and would eat more. I told my husband no, he’s gonna make himself sick if he eats any more. But is this normal?! I wouldn’t think that much milk could even fit in his little belly!!?