i personally don't think its a bad thing because if the baby doesn't have hepatitis b (baring in mind thats there's a 95% chance of that) and she does have an abortion, you wouldn't get a healthy baby. A baby is the best thing in the world so I think it's worth the risk. Forget all your worries for now, think about the good things in the future ie your baby, your future with your girlfriend or wife. No way is it a bad thing to to. Life is for sharing.
https://www.youtube.com/watch?v=VQ3d3KigPQM
i hope you feel better, go and live your life with her and your child. :)