Baby signs of autism ?

My baby is 9 months and had apoxia at birth so we’ve been holding our breath that he won’t have any health issues. Anyhow he seems to be doing well other than reflux and feeding issues but… he does this thing where he flaps his arm up and down especially when he’s happy or excited, but sometimes when he’s upset too. He’s done it since 4 months. And still isn’t babbling but he can make little noises. Can this be normal and should I just wait a little longer, or does it sound like he needs to be evaluated? I don’t know if the lack of babbling is an issue too.