It isn't likely a blood clot. You are too young and the symptoms are swelling and heat in the area, not chills. It sounds more like a cramp. Try heat, very gentle stretches. Eat a banana every day or have a glass of orange juice. Low potassium leads to muscle cramps and a banana or juice is a good source.
I've had chills down one side of my leg and pain and I read it could be a blood clot but I'm only 13 and I told my dad and he says its nothing to worry about. Please help?
Is your leg swollen, red, hot to touch & painful??? Are you short of breath or do you have difficulty breathing? If you answer no, then you don't have a blood clot.
It's better if you don't go on-line & try to self diagnose yourself.
It's probably just random pain and will go away soon. I get that all the time just try to ignore it an think about life being ok without a leg.