bottom line is - you and your current partner need to cover your std testing bases so that you won't have to worry like this when you get any symptoms. it's part of being sexually responsible and you should be discussing these things with your potential partners prior to being intimate with them.
grace
Update: The scab brushes off in the shower this morning which calmed me down quite a bit.
Thanks for the response CJC
I had the same thing a while back, although it was on my scrotum. I was assured that it was nothing to worry about. If it was a herpes blister, it would almost certainly hurt at least a little, or be itchy and irritating. Plus, herpes usually doesn't appear in the areas with the most hair from what I gather and it usually appears in clusters. That being said, always better to test and know for sure.