I started giving him breastmilk in the am and pm and formula the rest of the day and he picked up quite a bit of weight but then he got constipated from the formula so now I'm back to breastfeeding him mostly and just giving him formula if he wakes up in the middle of the night and once during the day. Luckily I had been pumping every 3 hours so I still had plenty of milk. He seems to be latched pretty well and my breasts feel empty after he eats but I really don't know because I've never breastfed before. When I was pumping I usually can get around 4 ounces each time so hopefully I'm producing enough.