So sores in the mouth are generally canker sores not cold sores, a big difference. A person with genital HSV 1 generally has few recurrences and little shedding. Sometimes people get it both orally and genitally at the same time at a sexual encounter. They kiss and receive oral sex at the same encounter. I know that you are HSV 1 negative but remember that that test missed 1-2 out of 10 infections so it is possible that the test missed it in you also. You may wish to consider obtaining a western blot to be sure for the future.
Terri