I once heard the following quote from a motivational speaker.
"If you want something you will find a way and if you don't you will find an excuse."
I believe the first thing you need to do is determine whether or not (you) really want kids period. There's nothing wrong with not having children. In fact people who don't want kids should not have them. A child is not a "gift" one person gives to another. It deserves to be loved and wanted by (both) parents.
Secondly if you have determined that you do not want children you have to be completely honest with your wife. Bear in mind this may be a "deal breaker" for her. Nonetheless going your separate ways is better than having a child whom you resent for bringing added stress, responsibility, financial expenses.
Now if you've determined that you really do want to have children then set a time to start trying to make it happen. Maybe you state a year from now. That will give you 12 months to start setting aside money. Maybe the two of you can work extra hours or part-time to pay off debts, get a bigger place, or simply build up cash reserves.
Consider your future options as to whether either of you will be a "stay at home parent" or if you will have to shell out cash for daycare. Find out how much that runs. In fact it may be a good exercise to put together the total cost of carrying additional health insurance, daycare, food, clothing, and so on. To be honest with you I believe most people just choose to have a baby and not worry about anything. They simply tell themselves "we'll make it work." That's not how I would want to live my life though. In fact I decided I didn't want children and elected to have a vasectomy. Naturally I was honest with every woman I dated about me not having a desire to have children. I also never assumed my baby would be born without life-long health issues. I imagine one has to believe (their) child will be born healthy regardless of all the news stories about babies born with various medical conditions.