I have strange bruise on the upper part of my left calf . It is hard non-protruding, not painful, dark, nearly black, and the surrounding veins had started to turn the same color this morning. I got it about a week ago, I didn t bump or injure my leg at all and the bruise came seven minutes after I felt a tight, warm, and non-painful feeling in my leg. When it appeared it quickly darkened to its current shade and no changes have been seen as of yet besides the vein discoloration. What could this be and what should I do?