Up until now my 4 month old has always been a great eater. Loves his bottle and was eating between 30-35 ounces (he is a chunkster at 15 lbs). For the past week he has been eating on average 20-25 ounces per day. He will eat about 3 ounces and then when he stops to burp and he gets super fussy after if i try to give him the bottle. He will turn his head away and sometimes even cry. I should mention I bottle feed him BM and he gets formula at night. He responds the same to both, but tends to eat a little more in the morning and eats less and less as the day goes on. Is anyone else having this issue? I am so frustrated and worried that he is not eating enough for his size.