Deep leg ache started in the thigh. Solution?

I have a deep leg ache that started about 10-15 days ago in my left thigh. Its point of pain is not known but felt. I cannot rub my leg and feel the pain but only when I am standing or sitting or even for a time leying down. I am in my early 70s and about 20 lbs over weight. We have a second level and the climb is not hard, 14 risers, but I notice it. Never had anything in my early life to describe it with the exception that growing pains somewhat describes it. It feels like perhaps a charlie hourse is about to take ahold of my left theigh. Jack Z