However, if you really do have herpes, and you have sex now and she gets herpes in
the third trimester
, that's when things could get serious.
You could certainly test now, before you go back to your country, and see what your status is at this point. Then, in 4 months, you could test again. If your test is positive for HSV 2 now, then I would notify her OB of this, and I would hope she would get tested also. If you are negative now, that's great, but not final.