Was the lesion on your abdomen swab tested? it is possible to have a herpes outbreak there. You must have thought that might be a possibility to have been tested for herpes. Do you know the status of your other partner, in terms of HSV 2?
I have seen false positives per the western blot at that IgG level, but not commonly.
Not everyone transmits HSV 2 to their sex partners. You could conceptually have been infected a long time ago (did you have other partners prior to your marriage?) and now are infrequently shedding.