You’re denying the obvious. 😳 I’m not sure how long you’ve been dating this guy, but it seems from your post that you started dating him after you were already pregnant with another man’s baby. Now that your due date is approaching in less than 10 weeks, he doesn’t want the responsibility of being your baby’s father or step father or surrogate step father. That’s why he’s backing off and reminding you that what you have isn’t serious. The more pregnant you’ve become, the more he’s had a chance to accept reality, and he’s decided he isn’t ready to be in a serious relationship with you. I know you want someone to take care of you emotionally and in other ways, too, but he doesn’t want the job.
My advice is to take his words seriously and don’t plan on co-parenting with him or even counting on him once the baby comes. You’d do best to get ready to be a single mother, and if you can enjoy his company, then do so, but don’t pretend that he’s part of your nuclear family. He isn’t — and he doesn’t want to be. At least not now.