You could have caught herpes, but from your description, I don't think you did. It sounds as though you have a small scab from irritation, nothing more. An acute attack of herpes from a recent encounter would produce not just a couple of blisters but swollen glands, fever, and so forth. I advise you to leave the scab alone and ignore it. If it doesn't go away in a week let a doctor have a look. Once the scab goes away, it may leave a mark for a while, but if the redness is flat, you should just let it alone.)
Take care.
Dr. Rockoff