I really doubt she would be pregnant. But if you havent already talked too her about your concerns, you should do.
If she dosent know already that there is a really slim chance that she could be pregnant you should tell her, like now.. Because if she is pregnant, its her body thats going too change not yours.
If she does end up being pregnant, she is either really lucky, or really unlucky- depending on your situation.
Ps.
I think its really sweet to see guys on here, shows that not all guys are bad, and that some do really care.