So you had one encounter 14 days ago, and 13 days ago you had two encounters with two different people. 7 days later you have developed symptoms of 3 possible sores.
Have you looked at yourself in the mirror? These flat pimples you are referring to that may burn after urination, may very well be sores or blisters. You should look at it yourself.
You really need go to a doctor as soon as possible and get it visually checked by a professional. HSV-2 can have initial outbreaks from 2 - 20 days typically. Once checked at least you will know what you have instead of guessing and losing sleep over the what-ifs.
It does sound like it could possibly be herpes. Just because you didn't break out after the other times, doesn't mean anything. They may not have ahd a break out during that time, so it wasn't transferred to you. You really should have it checked.