I highly recommend that you talk to your doctors
">primary care doctor about this issue. This is because there are 3 main types of hepatitis, A, B, and C. There are vaccinations for hepatitis A and hepatitis B but there is no vaccination for hepatitis C.
Hepatitis A is a food borne illness
usually that is picked up when food or water is contaminated by fecal material containing the hepatitis A virus.
Hepatitis B is usually a sexually transmitted infection in adults. Other ways of picking up hepatitis B include sharing infected needles or mother to baby transmission
Hepatitis C is usually transmitted from one person to another by sharing infected needles. It can also be transmitted sexually, although the risks of that are much lower than with hepatitis B.
As you can see, knowing whether you are at risk of catching hepatitis requires knowing both what type of hepatitis you were vaccinated against and also what type of hepatitis your girlfriend has. I strongly suggest that both of you see your primary care doctors immediately to help sort this out. In the meantime, you should have only protected sex until you are clear of what precautions you might have to take.