Could Exercising Cause Red Blotchy Color On Thigh?

I have been working out alot more than noramal about 3-4 times a week. My left thigh is a red blotchy color all of the time. Except for when I am clod and then it turn kind of purple. My thigh does this as well but not to the same extent. I am not overweight i am 5'1 and weigh 115. Could this be from excercising or should I get it checked out?