Anyone have a skinny baby?

My son was born around the 50th percentile at 7lbs 7oz but dropped 10 percent in the hospital and has been slow to recover. We supplemented with formula in the beginning until my supply was established and he was back to birth weight around 2/2.5 weeks. He’s almost 2 months and according to my weights at home using our regular scale he’s still under 10 pounds. At 1 month he was at the 8th percentile for weight (but he’s long, 90th percentile for length).

He seems happy and alert, hitting all his milestones, eats well, has lots of wet and dirty diapers, but still he’s just not fattening up. I’m breastfeeding and have seen a lactation consultant twice, both times they were happy with his latch and how many ounces he got during the feed. I’m feeding on demand. In addition I usually pump once a day and get anywhere from 2-5oz.

Anyone else also have a skinny baby? I’m worried he’s not gaining weight quickly enough but otherwise he seems great. He has his 2 month check up next week and I’m dreading it, I think his weight is going to be really low.