I am far from an expert on herpes but i have read OVER and OVER on a lot of threads about the Igm test being a complete waste of time. You should go back and ask for a herpes select specific Igg test. It will be able to differentiate between HSV 1 and HSV 2. And 6 months after exposure is sufficient time. I believe the window is 4 months so you should get accurate results with the Igg test. But you could wait for someone else to tell you like I said I am not a expert.
All herpes questions need to be posted in the herpes community, they will have the best info for you. see the link above.