how many ounces does your baby eat?

I breastfed my baby girl for her first month of life outside the womb. I didn't have a lot of milk so she was always hungry. Doctor said I could put her on formula and we started out with just two ounces while I was still trying to breastfeed her. Then I stopped breastfeeding completely and she started taking 4 ounces Every two hours since she started the formula. Does anyone else give their baby a lot of formula? She doesn't spit up anything so I know she's not eating too much. She's seven weeks this weekend. Doctor said to feed her every 4 hours but she is always hungry at 2 hours she will not stop crying no matter what I do. I carry her, talk to her, change her diaper, give her pacifier, everything. And she's doesn't stop until I give her a bottle. So, how much do/did you feed your baby at this stage?