Hello,
Whether you know it or not you probably have the oral herpes virus (HSV1) already. Worldwide, more than 90 percent of people are seropositive for HSV-1 by the fourth decade of life. It is possible for there to be cross reactivity (HSV 1 causing genital herpes and HSV 2 causing oral herpes).
I would believe what your gyn has told you and take care of yourself accordingly.
Best regards,
Dr. Downing