Mine is the same, she was 10 weeks on Monday. I was worried so have been to have her weighed today and she is still on her percentile line and they said not to worry. Their stomachs are only the size of their fists so some will take more than others.
I would only up it when he’s literally drinking every single bottle and leaving nothing in it, my little boy is 3months Saturday and he’s now on 7oz as he was literally devouring every 6oz bottle and wanting more, he goes every 4 hours , some days he’ll have 4 bottles and some he’ll have 5 x
My little girl is just 9 weeks and we've recently increased the dose to 6oz every 3/4 (5 times a day), but right now she does not finish the bottle. Every baby is different so ask the GP/health visitor. I was told that as long as the baby gains weight and remains in their percentile, it should be fine.