Tingly Heel

I'm 6 foot 4 and 18 years old.

In the last 3 days my heel has started tingling at random times but more frequently.  
It seems harmless: no pain, no visible problems beyond a red spot that comes from my tight shoe.

It is strange, however, because no part of my body has ever tingle more than 30 seconds. This, however, has been going on for 3 days, on and off.
The only thing I can thing of is a pinched nerve, which is possible since the AP exams I took were 3.5 hours with only 1 five-minute break.

I hope I'm just paranoid.

Thanks!

[Truthbetold1]

I'm 151 lb if that helps.