For the last four days my 11 week old has been spitting up her entire bottle at least once a day. She has been drinking the same formula since she was born and everything has been fine up until this point. She was drinking 4-5 oz everything 3-4 hours. I thought maybe she was drinking too much so now I only offer her a 4 oz bottle. I burp her every 5 minutes and keep her upright for 20-30 minutes after finishing the bottle. She seems fine otherwise, she doesn't have a fever, is smiling and kicking. I'll be taking her to the doctor tomorrow but wanted to know if anyone else has experienced this with their baby and what the problem was?