I don't even want to pretend to know what you are going through right now. Having someone you love on one hand and having someone who is truley a part of you on the other. It's a really hard choice to make. I don't want to tell you what I would do because I'm not you. I do think it's easier for him to make a decision than it is for you because quite frankly he's not a woman. He can't see things from a womans point of view. He doesn't have a life growing inside him. He doesn't know how it feels to have someone totally dependant on him for it's life as you do. He will never feel the bond that only a Mother and her child has.
Make the choice that is right for you. If he really loves you he will listen to you. He may not like it but he will listen. Explain to him how you feel. Try and make him see that the child isn't just cells but is a real human being. It's his child. It's his boy or girl.
If he wants to wait till he has done everything he wants to do before having a child then that day will never come. I have been there. I kept telling my wife I wanted to wait till we were ready financially. We waited for years but we never seemed to be where I wanted us to be. Finally I woke up and saw how much it meant to her to have a child and gave in. The funny thing was that we found a way to make it with what we had. Things are better financially now and my son is 12 years old. I am so glad I didn't wait. I don't want to think what life would be like without him.
Good luck with whatever you decide. I will look forward to hearing from you again. Keep talking and we/I will listen.