It doesn't seem like you two are in a relationship from what you have said, so until the baby is here there really is not much he can do. If he is reaching out don't try to shut him out.
It's crazy that social media plays such a huge part in communication, blocking\deleting him would be wrong especially if you want to get child support. He could show judge or dcs worker that he has been trying to communicate with you and that you resisted any help from him by shutting down one of the ways you communicate.
If he is asking to be invited then I think he might have had a change of heart.
Block him. If he really wants to make an effort in being there for u and your child. He will do it in other adult like ways. U don't have time for the drama. U and your baby are the main focus right now..
He might had a change of heart.
I would add & invite to babyshower,
but only so he can't claim in the future that YOU shut him out.
Once baby is here, ask him to pay child support.
If you already need help with medical bills, save them and split them down the middle and present him receipt copies (you keep original in case you need them for court) and ask him to assist.
Good luck <3