I am active, healthy and strong, just turned 51, female, exercise class twice a week, pretty busy, no allergies or medications. For the past two weeks my muscles and joints are achy and actually hurt. They feel stiff like I did a new exercise and then did not stretch. Have a big red bump that I thought was a black fly bite, it is sore and hard on my shin like I bumped it. Does not look like a tick bite. Any ideas why the aches?