I had a cold sore that i believe was gone before my boyfriend and I engaged in Oral sex. How Long is Hsv1 contageous.

Always.

Even if you aren't showing symptoms of a cold sore, you are still considered contagious. The virus goes through periods called shedding, where it is active in your body but you aren't showing symptoms. During these times, as well as during outbreaks, you can still spread the virus. Problem is, you can't tell when you're shedding, so you must consider yourself contagious at all times.