First of all. I don't know how easy it is to divorce-bust while you are pregnant.
To be honest, to give you a "deadline" while you are pregant with his baby is, frankly, in my opinion, obscene.
He deserves to be horsewhipped for putting any pregnant woman through that. You don't need that kind of anxiety while you are carrying a baby.
I think you should read the Divorce Remedy. And then book 3 sessions with a DB coach.
I think the basic keys are:
1. Don't pursue or chase him or try to get him to work on the relationship. It will only make him pull away.
2. Be kind to yourself -- you are pregnant.
3. Do things for you. Have fun, get a life, as they say.
4. Take this time to find yourself. Do things a little unusual. Pick some hobbies that will consume your mind and attention.
5. Honey, I hate to break this to you: you don't NEED a man who will abandon a mother with a 5 month old baby (in May). It's purely disgusting. Setting a deadline like that is pure evil. I hope this thought helps you to detach a bit. Maybe he will change into a real man