So I have been breast feeding and I went back to work and type of job I have makes it really difficult to steadily pump throughout the day and so my milk production has way low. And now I give her half and half bottles. Half breast milk (I still pump when possible) and half supplement. And it's a full 4 ounces. I haven't had any problems with it but I'm wondering when should I start giving her more ounces per bottle? My baby is four and a half months old!