My fiance found out that he is postitive for hep. b (chronic).i am a nurse. i have been immunized and am immune.what are my chances of getting hepb?

Probably very low ..: If you got your hep b vaccine over the age of 6 months, most studies show long-term i.e. > 20 year immunity to hep b infection. Assuming that you are not immunocompromised and you have been tested to be immune now, then re-testing or boostering should not be necessary. I would also make sure he does not have another other communicable std's i.e. Hiv, hep c, etc.