The igm test is pretty much meaningless for herpes. Totally disregard the results of it and don't allow them to draw it on you again ever .
http://www.medhelp.org/posts/show/248394 is a prior post that goes into more details as to why not.
It also appears that you had a non-type specific igg test done which is also normally worthless. Yours however is negative so really no reason at this point to seek out additional testing.
What led you to get tested? How long after any sex act that you were concerned about did you have the testing done?
grace