Overfeeding?

How do you regulate your baby when it comes to how many bottles/ounces per day while exclusively pumping? My daughter is hungrier somedays and eats more than what is "recommended" but I always make sure she's truly showing hunger cues and I only give her more in one ounce increments to not overfeed. However, the pediatrician said her spit up and reflux issues could be a result of me overfeeding and she doesn't want me to give her more if she's had a certain amount within a certain amount of hours. Any advice or tips on this?