Well, all I can say is think very hard about bringing a child into the world if either of you aren't certain you want one. VERY hard. Also if you aren't certain about the future of your relationship with this woman. A healthy child deserves a *stable*, nuturing life. Its not like a pet you can give away in a few years.
There are enough poorly-raised, unwanted kids on this earth. Only bring one into the world if you have LOTS to offer (both of you, this post is as much for her as you). Tho not all will agree with me, you do have choices. Quality of life is much more important than quantity. We got lots of quantity on the planet these days.
Think very hard, and make your choice based on what is best for the child. Not what either of you want.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh