Hugo
Going back 15 or 20 years ago some of the early herpes tests had some cross-reactivity to antibodies produced by other members of the herpes family. Today, that should not be true with any of the modern tests. Was your swab a culture or PCR and if a culture, was it type-specific? There's still an unfortunate tendency for some doctors to do non-specific cultures and then assume type 2 if it's genital. The PCR analysis is great because it looks for viral DNA through Polymerase Chain Reaction and is very sensitive and specific.
Regarding the sores in your mouth.. Those are not too likely to be oral herpes. Oral herpes is generally around the lips and it's not uncommon to confuse canker sores with cold sores, but they're not at all related.
I'm a little frustrated about your percentage results as I've not found any tests that express the results that way.