I was just talking to my DH about that today...if we couldn't have children. We are on the same page when it comes to that though...I don't think we would pay for it as it isn't 100% when you do it and it is so expensive. But then again, I have not been through years and years of trying like some women. So I am sure I would think differently perhaps.
I would be discouraged if DH flat out said he wasn't going to do it. It should be discussed between you both before anything permanent is made. Try not to stress over it, he probably just made the brief comment and stopped thinking about it.

If he wants another child as much as you do, then I am sure you both will decide what you need to do to make that happen

With all that is going on with you, he should understand that it has been hard for you

Hope you feel better soon.