You're getting ahead of yourself.
Calm down and think of this slowly in steps.
First thing is first - you need to know if it is your baby, and more to the point you need to know if she really is pregnant first.
If she is and she says its yours, then you need to talk about your options. You don't want a baby, maybe she doesn't either. Then the solution is a somewhat simple one with abortion although you'll carry that scar for your life no doubt.
If she is pregnant, if its yours, if she does want to keep the baby, but YOU don't want to. You don't have to be involved. Morally it may seem wrong but if you state your feelings from the start of this so that she is clear where you stand then you don't have to be involved. Of course, feelings change over time, and a lot of would be parents have naturally panicked about parenthood until they see their child for the first time. Maybe that can happen for you. Maybe seeing a little life that you've created will make you realise that you don't want to give it up, don't want someone else raising your baby.
Of course though, that is a long time off.
You have time to think about it properly and talk with the girl and work things out.
Even if she is pregnant with your child, your life isn't over. Hardly.
Just stop panicking.