Hi,Thanks for query.
As you have got pain in right thigh and if you got stones in right kidney then there is possibility of having referred pain
on that area.
As you are 50,there is a chance of having some problem in your vertebral
spines.Due to osteoartheritis of spine there might be some nerve root
irritation giving rise to this pain.
As your problem is since lat 2 days,it is possible that you might develop Herpes zoster
as in this condition pain starts first and lesion develop afterwards.
Go for x ray lumbo sacral region.
Take some pain reliever medicine.
Ok and bye.