Rashes can be for so many reasons. The worst thing to do is type into google HIV rash - because most of them are not. Many are heat rashes, prickley heat or allergic reactions.
As Iwan said, your risk would be said to be minimalist(if any).
I had a rash on my back in the correct HIV window and I was convinced it was....... but no, it was an allergic reaction to medication.
If you find that you can't relax your mind about this and worry starts to make you sick, Just get a test. Then you will have peace of mind.
You had no risk of HIV on the exposure you've described. Folicitus is a common condition and is not really linked to HIV.