The other day, while at work, the middle of the back of my right thigh started hurting horribly bad...out of nowhere. About 4 hours later, the pain moved down to my calf. At the same time, I kept getting real sharp pains in my right heel. All the while, it even felt as if my skin hurt. Here it is, 3 days later, and my whole leg aches and I also keep getting random sharp pains in my calf. What could this be and should I be worried?