I Have A Small Bulging Blood Vessel On Left Upper

I have a small bulging blood vessel on left upper arm next to elbow which also has a purple so t or bruising . It was soft to the touch - the bulging ball like seemingly a busted blood vessel , vein , ! Don't believe I hit that area with anything. Am worried. I placed a bag of ice on it and has become flattened and not as soft and round as before. Don't u s u ally get bruising or soft bulging like this so startled me . As it is 3a.m. central time and was already almost asleep when I you c h ed it and got up to look at it in mirror . Should I worry of blood clotting? This is unusual. Have not had any blood clotting before but since it's the left arm. Only take Alendronate once a week. Took Tylenol for back & right arm injury pain . Please help