What should I do? So like I've shared before my ex left like when I was around 3 months I'm soon to…

What should I do?

So like I've shared before my ex left like when I was around 3 months I'm soon to be 5 months now and I having conflicting thoughts when he left he said he was sure that it wasn't his baby and wanted nothing to do with me but since there was still the possibility of the baby being his he said he would still go to appointments. But of course two months have gone by and not once has he made the effort to contact me to ask about the baby or has ever gone to any appointment up to now I've had family and friends go with me to doctors appointment and ultrasound appointment. I have not bothered either not once to try and contact him about anything. So I have an ultrasound appointment coming up in the 14th of June so I have debated with the idea of trying to contact him and let him know about the appointment or not. Part of me wants to because at least I can say I tried to involve him but another part of me thinks that he made his choice clear and he wants no part in it if he wanted to be part of it or cared at all about his son he would have made the effort. It's like he left why should I have to be the one to reach out. I'm just so confused on what I should do any advice on what you guys think I should do?