You don't mention when this happened. If it is after April, you can get tested for std's if you desire just to rule it out officially but I don't think you have an std. I think you have a wound from the act itself unless it was a long time ago. Sorry you have to worry about this. I don't think I'd be overly concerned from your description.
I don't see anything in the photos. Oral sex is not a typical route for herpes as it would then be herpes simplex 1 transferring to genitals. It CAN happen but is not common. That often looks like a blister as well and hurts. Warts? The scratch may just be an abrasion from teeth or something. How long have you had it?