Y'know what? I may be a lone voice here - but your g/f got pregnant with your help, yet before you had sex with her, the two of you never discussed possible outcomes. So that, frankly, takes you out of the ring for the decision of what to do now.
If you had been responsible, and had had a talk with her before you ever had sex about what you would do *if*, you wouldn't be in this situation (and you'd have a better leg to stand on, if she then went against what the two of you had previously discussed, tho it's still her decision). But you never had that talk, so here you are without a leg to stand on.
Leave your g/f be! Babies are not always the godsends people say they are. They do change our lives completely and if she's not ready for that, you can't force her to be. Even pregnancy changes our lives, and if she doesn't want it, she doesn't want it. Period.
If she chooses the abortion, *support her* dammit! Stop scaring her with exaggerated stories of what abortion might do - that she may not be able have kids later. Gimme a break. (if abortion made so many women infertile, abortion opponents couldn't claim that women are getting multiple abortions as their means of birth control!!) the doctor can tell her the *real* risks, not the ones you've heard thru the grapevine.
Drive her to the appt. Hold her hand, pick up her prescriptions, give her her medications with a glass of water. Do not hold it against her. You love her? Forgive her.
If you can't, break up with her. But quit laying guilt on her. It's a crappy enough decision to make as it is without you being an insensitive jerk and making it worse.
And let me tell you another story - my cousin convinced his g/f to have their accidental baby, he said she'd become a good mother. The mother ended up an absentee mother - imagine that, and a little girl with an irresponsible mother as her role model - and my cousin ended his college life to raise the daughter. Yep, his life, his ambitions, his goals, they ended. He's come to terms with it, and he tries very hard, but his daughter has a crappy mother to show for it. Stupid.