This is a tough one for the following reasons...
1.) Kids annoy me
2.) I don't feel responsible (in a fatherly way) for a kid that's not my own
3.) If you love a girl & she loves you, then a kid shouldn't matter 1
1But you usually don't start loving a girl until you've at least spoken to her a few times (unless it's love on 1st sight) and I truely hope she'll tell you about the kid before that happens (she's not really honest & thus trustworthy if she doesn't)