My 6 & 1/2 week old has been eating 4oz bottles (part breast milk part formula) every 3-4 hours, the past couple days he's fussy when done eating, I don't want to over feed him, but just now he started crying when his bottle was empty so i gave him a little bit more and he seemed content and sleepy, to me that means it's time to increase his bottles a little bit, is that right? Or are there other signs I should be looking for?