Hi there and thank you for the question. I am a Registered Nurse and will be happy to help you today.
Two scenarios here......either the HSV2 test a year ago was erroneous (incorrect) OR your boyfriend is a carrier of HSV2 (means he's been in contact with the HSV2 virus) and passed it along to you. You can get HSV2 and not be symptomatic (have no symptoms), so he may have it and not know it. Did you actually SEE his test results or did you go by what he said (that he tested negative). Let me know if you actually saw his results or if he just told you that his test was negative.
Ok thanks for the added information.
Don't be confused. You were HSV2 negative going into the relationship. You don't know if your partner was or was not....most likely he was HSV2 positive. If he was the only person you have sexual contact with after you tested negative, then it most certainly looks as though he is the guilty party (meaning he was the one who passed it along to you). Reply back if I can help you further.