2 month old eating TOO much?!?

Samantha
Alright in my house we have been back and forth to bump our almost 2 month old up to 6oz yet (3 BM & 3 formula). We have him at 5oz currently and he seems to be wanting more. We have done 6os only at his feeding around 10pm and he eats it with no problem. 
I'm just worried we're going to make our son "fat" or over feed him.
When he was born (c section) 7/6 he weighed 9lbs 10oz! So he wasn't a small baby at birth. At his 1 month check up he weighed 11.1 & was 22.5inches and his dr didn't seem to be concerned..
Any insight would be great!!