Am I overthinking?

So I am currently pregnant with my second babe, due in November. Same dad for both kids.

Throughout this whole pregnancy my SO has not shown any interest in it, aside from coming to ultrasounds. By that I mean he doesn’t touch or talk to my belly/baby as say other dada would.. Hasn’t gone out and bought anything for her. He’ll post about her and how happy he is to meet her on social media but nothing physical shows he actually is... my son on the other hand (2yrs) is constantly talking hugging kissing singing to his baby sister and it’s just like, can you take notes? I mean I find it kind of upsetting? Not really sure how I feel about it tbh.

I’m thinking he doesn’t even want her at this point. Anyone else go threw this? Am I over thinking this whole thing. I just feel really upset that it’s like she’s almost non existent to him?

TIA