My 3 week old recently just started eating 4 oz and he's about 8 pounds... But lately he's been eating the 4 then wanting more ? Or not seeming to be " full" from it. We burp every one to two ounces and he absolutely hates that your taking the bottle away to burp him so he'll cry and scream. Anyone's baby do this ? I try to keep him ok till like 2 to 3 hours later then he can have more if he wants but it's hard bc he seems to not be full and I am not sure we should bump it up to 5 this early help please