wow. doctors are ridiculous sometimes. i went to my college's health center last week to get a blood test to confirm which type i have (i found out over 3 months ago i have hsv genitally when i got an outbreak) but they said they'd never heard of a blood test for herpes...that the absolutely only way to test was if you were having an outbreak. then i asked "well what about the other 90% of people with herpes that have no symptoms? can they never get tested?" and the doctor sort of chuckled and said "oh trust me...you would absolutely know if you had it. it's extremely painful."

anyway, to answer your question, you can absolutely infect a woman even with no symptoms.  granted the odds are a lot lower for you than for people who get oubreaks. the guy that gave this to me had never had any symptoms, orally or genitally.