Was it an IgG test?
If it was an IgG test, and not an IgM test, that's not all that surprising. The HSV1 IgG test misses about 30% of hsv1 infections, so it seems as if yours is one of those.
If you feel the need to confirm your infection, though the culture is the absolute best way to get a diagnosis, you could get a Western Blot test, but you really don't need it. It's up to you, though.