I just recently got genital hsv1 from my fiance and he didnt even have a cold sore present at the time so unfortunatly it is possible.
washing up after sex doesn't do anything but make you smell better. It doesn't reduce risk. The virus is transmitted during the sex act itself, it doesn't lay on the skin and work its way into your body to infect you.
Do you know your own hsv status? Have you ever had a cold sore?
In the future, it's best never to receive oral sex from anyone who has a cold sore present, no matter what the stage. Also if you don't know the std status of the person giving you oral, it's best to wear a condom. I know - now I tell you.
Nothing you can do now but wait and see. If during the next couple of weeks you develop any obvious genital symptoms, see your provider within 48 hours of their appearance for a lesion culture and typing as well as treatment if they feel it looks like herpes.
grace