9.5 month old-breastfed well baby exam

I still breastfeed my 9.5 month old and offer “solids” 2-3 Times per day...sometimes more if he isn’t showing interest in one of the feeding sessions. I nurse on demand and I quit my job several months ago so I haven’t pumped since then. I have always just nursed from one side during one nursing session. I offer the other breast the next time he wants to eat. He nurses around 7-9 times per day.

We just had our well baby exam and he is in the 33rd percentile...at his six month exam, he was at the 57th. He has been sick for about 3 weeks with a lingering cough, congestion, and what we just found out was an ear infection.

He is meeting all of his developmental milestones, but the doctor framed it as though “he didn’t grow as much as he could have.” While we were leaving though, he said my baby looks great and to offer a bottle of pumped breastmilk after I nurse him. I have been doing that and my son only seems to want to chew on the bottle nipple and treat it like a teething toy and not drink any of the additional milk. The doctor said I could also pump and see how much milk I have been getting...I did that and it’s less than what I used to pump.

I am concerned of course, but my son always seems satisfied, is meeting milestones, and is a happy and engaging baby (even when sick and with an ear infection). I also started nursing from both sides during one feeding (he nurses for a little bit from the second side and then just uses me as a pacifier).

Has anyone else been told this? Just looking for advice or words of wisdom...