Disappointed

So my little guy is supposed to be here in March. I’ve been super emotional my entire pregnancy so I don’t know if thats most of the problem or if I’m really just that hurt and pissed off... but my dad has always been a bitter man. He’s hated my mom for 20 years ( I’m almost 23 ) but he’s always been so loving towards me and my brother so when I found out I was pregnant I told him right away. My SO and I had been trying for 2 years and I was diagnosed with PCOS at 19.

Anyway, I would keep my dad updated on what I found out at my appointments, right? like I did with my mother and siblings and he never really texted me back or even said anything. In fact, hes seen me one time since I told him I was pregnant. Even when we found out the gender I texted him and asked what he thought it would be and all he said was “boy” and when I said yes and filled him in on the other stuff like heart beat and whatnot, he never said anything back. I know its not really a guy thing but he shuts down every single time I bring up my son. I invited him to thanksgiving dinner and he declined because my mom and step dad would be there but completely ignored my offer to schedule a dinner on another day so we argued for a little while because he promised he would start coming around more often and coming to birthday parties for my step kids to get used to it all when the baby arrives. I asked him if this meant he wasn’t going to be around for my sons birthdays and he said nothing and still hasn’t said anything to me. At this point, I’m ready to cut him off because he shows zero interest in my son’s life to begin with. I’m just so angry with the thought that he can’t put in any effort at all to give a shit. it makes me feel like my son means nothing to him and if thats the case, I wont stand for it. Am I overreacting?