I applaud you for taking responsibility, but in all honesty, you should get a DNA test. You know nothing about this girl, she may not even be fit to raise a child…Is it really offensive to ask for a paternity test from a woman you had sex with at a party? I could see if you were in a relationship, but that's not the case. If she flips out, well…she has a problem understanding logic IMO…
If she's going to keep it, you should definitely try and make it work and be a father. Good luck and I hope everything works out.