When I fell pregnant with DD, I was 20, renting and not in an especially good job. It was a bit of a struggle, but we managed. Like MadB said, babies can be dirt cheap especially when they're little. Remember that very few of those expenses that financial planners like to scare you with have to be paid all at once upfront, other than a few initial items like somewhere for bub to sleep, car seat, pram etc. And even those things can be found relatively cheaply second hand if you're so inclined, or can vary incredibly in price for brand new. Very few of the things baby shops try to tell you are "essential" are really all that necessary once you're past the basics.

One thing I did find helpful this time around was to do a trial run of living on one income for a set period to see how the finances would look. My income was used to pay off a few debts and to buy the initial outlay type stuff for the baby then build up some savings. If you're partner is on a decent wage, maybe try this for a while to see how well it'd work then decide if you're ready to take the plunge?