Dude she could always have an accident, maybe you give her a ride to the hospital and accidentally slam her side of the car into tree or something.
But in all seriousness does she actually know your real name? If so you fucked up, you never let dumb bitches know your real name cause if they don't know that shit they can't track you down or put you down on any paperwork.
It sounds to me like you are making the mistake of telling this chick you will be the father of this kid if she ends up keeping it. You need to make her know if she keeps the kid her life will be a living fucking hell. Also make her think its not yours by getting some doctor to tell her your sterile or some shit.
As much as you want to do the responsible thing or whatever just know that anything to do with this chick is going to be a living fucking hell for the rest of your life. You live in chicago aren't there some ghetto hood rats you can pay a few bucks to to beat this chicks ass so hard she has an miscarriage or some shit? Seriously man this is the time you need to get creative in, focus all your energy on figuring out a way for her not to have that kid.