Right now you hold all the cards. He does not like that. He is trying to control the situation in the face of having no control.
Remember this:
He knows you know- you've shown him what ow shared and his response has been cold and callous.
👉🏻He has purposefully not asked about you, your welfare, your child, your unborn child.
👉🏻He has purposefully not offered an apology or explanation.
👉🏻He has purposefully shown no interest in seeing your child.
👉🏻He has purposefully not attempted to excuse his affair.
He is very clearly saying he doesn't care about you - he is saying he holds you in utter contempt. He is a nasty bastard.
At this point you don't know what he wants or what his end game is. But you do know what you want. He doesn't know that though and the longer you keep your powder dry the longer you'll have control over the situation, and can deal with it on your terms in your own time to get the best outcome for you and your children.
The minute you respond to him you'll be ceding some control so give him the absolute minimum you can, keep comms focused only on what you need and language completely impersonal. Do not offer him any insight into how you are, he hasn't asked but he can see you're absolutely bossing this by your actions so don't say anything that might contradict that. He hasn't asked about or expressed a desire to see your child - so you do not need to offer this up. He knows you're physically vulnerable and hasn't asked about you/your babies health so you do not need to reference this.
What you need from him is him not turning up unannounced at your house, so this and only this should be the focus of your comms.
Even more powerful if it comes through a third party and not you.
Use chat gpt to refine the message if it helps!
I'd say / get a third party to say something like:
I don't need contact with you right now. You will be informed when my baby is born. For anything of yours you need from the house make arrangements with xyz.
Your dignity and self respect, the love of your children and family and when your baby looks at you with adoring unconditional love, will make the pain of this will be bearable.
❤️