No, this does not sound like herpes to me. I think you are using the word vesicle in a way that likely doesn’t support what vesicles are. They are water blisters that have a tense surface and break. Do you really have water blisters in all of those places? I think at least on of the providers that you have seen would think it looked like genital herpes if that’s what it was. Herpes lesions are most definitely distinguishable from the skin around them. They usually, with first infection, hurt some. They are not at all flat, they are raised and distinct from the skin around them. I don’t believe you would see them in all of the locations that you are describing either – not torso and arms and if they were on your hands I think you would definitely be having discomfort. Also, I don’t think that the symptoms would last for three weeks without changing – if they were herpes, they would definitely be changing over time from water blister to ulcers in the skin to crusts. Herpes lesions with a first infection are just not so small they are painless, normally speaking.
Have you ever in your life had a cold sore on your lip?
Have you discussed your concerns with the person you had sex with so that they may get tested and then you can know if you really have risk?