I have to agree with xepherys... the chances that your gf is pregnant from precum that you may or may not have had on your hands when you fingered her are so very remote... I'm going to have to say that she's not pregnant. If I had money, I'd bet it.
I've had at least one pregnancy scare with both serious ex's, and two scares now with Xeph. The first time I was just a few days late (still adjusting to a new BC), but the second time I had several legitimate symptoms. I had nausea/vomiting in the morning, restlessness at night, and my period was late. But, after I thought about it, I realized that it was *probably* just the stress of being in the last month of combat medic school.
Still, I bought a test to put my mind (and xeph's) at ease. Negative, of course.
My point is, if you've been as careful as you say you have in keeping your semen away from her vagina, then she's not pregnant. After a $15 pregnancy test confirms it, I would consider getting her on some birth control in case you end up going past hand jobs. Definitely better safe than sorry, eh? Two words: Planned Parenthood.