Skin Blister/Bump in Groin Area

I am 24 yr old male, no sexual contact for past 3 years.  I woke up this morning to find a mildly itchy white raised bump on my inner thigh.  Very close to the crease between my leg and my scrotum.  It looked exactly like a pimple would like in an area where the skin can not be raised sufficiently to like a  pimple on say, the face or back.  It was flat, small, could fit inside my pinky finger nail. Bigger than a pin head, smaller than 1cm.  Standard zit size.  It looked ready to burst.  I squeezed it, nothing happened.  I squeezed it harder, no pus came out, the skin did not break, no pain, no itching.  I ran my finger over the blister/bump in a soft, lateral motion to determine how raised it was and how much pressure was there but as softly as i pressed, it tore the "head" of the blister and what was left was a red dot beneath, the "head" which was now torn skin attached to the unaffected skin and maybe a pinpoint of blood if that.  There was no liquid, no pus, no wetness on my finger.  The spot became immedietly itchy, burning and sore to touch.  I had a shower, insanely scrubbed the area, put a bandaid on.  

I've been trying to diagnose it myself on WebMd.com but there are too many things that fit the description.  The dot was NOT there yesterday.  it is too itchy to be a zit, plus it didn't burst when squeezed.  I am wanting to make sure it is not a latent form of an STD like herpes or syphyllis, or cutaneous anthrax, or HS.

Any help is appreciated.  Thank you for your time.