Hello, I had unprotected sex two times with an ex girlfriend of mine 11 days ago. The first encounter was 2-3 minutes, and the second encounter the following morning was 3-5 minutes. 8 days after the encounter (3 days ago), I noticed a small, red patch of skin, about the size of a penny, on the inner/back part of my thigh. The skin isn’t raised, there aren’t any lesions or blisters, and the red area is smooth to the touch just like the skin around it. It almost looks like a bruise and the appearance hasn’t changed  since I noticed it 3 days ago. There haven’t been any changes or abnormalities to the shaft or head of my penis, and I haven’t had any other sexual encounters since testing negative for all STIs a few months ago.  

This sounds nothing at all like herpes to me.  Recurrences can happen on the thigh but generally speaking, we see first infections show up in the area exposed - which for you would be the shaft of the penis.  Herpes lesions appear as water blisters on a red base when they show up on the thigh.  You aren't describing that at all.  And I would expect HSV to change over a three day period.  It is normal for some redness to show up first, but three days is a very long time for it to be just red, without any blisters forming at all.  This doesn't sound like herpes to me, but if the red area changes, and becomes raised and fluid filled, have it swab tested.  I doubt that it will.---