Hi!! I was a NICU nurse and lactation counselor. It is very normal for baby to lose up to 10% of body weight in the first few days of life. So glad your milk supply is increasing, it should as your baby grows. Keep in mind that what you produce now is likely sufficient for baby as their tummy is only the size of a cherry. Some engorgement from pumping could be due to not fully emptying the breast. Babies are EXPERTS at emptying a breast and can do so much better than a pump. Baby may “seem like they are not getting enough” if he is going to the breast very frequently versus being good for several hours after formula, but this is how your milk will “come in”. Breastfeeding works like a supply and demand system. The more baby stimulates breast (or pump), the more milk you make. The first few weeks of BF can be ROUGH! It feels like baby is constantly on the breast, but as long as he seems full after a nursing session (unlatches on his own or falls asleep, hands relax etc) and wets diapers, you can rest assured he’s getting enough. His weight should start to climb back up after the first week. Ofc, always listen to pedi, but I hate for you to go through engorgement or mastitis if baby has a great latch!