I think you'll be fine assuming your test was negative at 4 months. I sound like a broken record but in order for hepc to be transmitted blood from an infected person MUST enter the bloodstream of another person. Just because you have a cold sore doesn't mean this will happen even if the blood makes contact with the sore.
Trinity
Many of us have been in relationships which have involved a lot of kissing, and even more believe it or not. This is not worth your worrying about in my opinion. HCV is transfered blood to blood, not blood to saliva, or saliva to saliva.