Hello, I have a fluttering or vibrating sensation in the bottom of my heal of all places. It comes and goes every few seconds. I have taken off my shoes and it is still occurring.Today is the first time I have noticed this.I haven't done anything out of the ordinary in the past few days, nor am I wearing any restrictive clothing (with the exception of nylons that I have worn many times over. Should I be concerned about a clot somewhere in my leg?