Canker sores are not herpes.
that said - you can have canker sores and also have oral herpes. there isn't an easy way to determine if you contracted hsv1 both orally and genitally around the same time unless you get obvious cold sores ( and not your normal canker sores you've been getting ).
when you have canker sores - don't perform oral sex on a partner. They are an open portal into the body for germs.
grace
I'm assuming your genital HSV-1 was diagnosed with a viral culture. If you had oral HSV-1 since you were 13, you probably would have been immune to getting it genitally. Canker sores and cold sores are different, to my knowledge. Cold sores from HSV-1 usually occur outside the mouth, somewhere on the lip...not inside. Anyway, try not to let this get you down - if you do have genital HSV-1, you will probably not have many outbreaks, if any more, and they will be less severe than if you had HSV-2.
Good luck,
Em