sharp stabbing pains in legs particularly left leg

I have had this pain one and off for many years! I have tried X-rays, bone scan, MRI of my lower lef, physical therapy 3 different times...to no avail. I actually have a soft tissue lump at the site of the pain. It comes and goes completly randomly...during physical activity while sitting in a car, at night in bed...doesn't seem to have any rhyme or reason. I am an avid walker..I do ride a bike, but only occasionally. I read about the person who took the Aleve and stopped exercising for 2 months...what are your thoughts?

Hello and welcome to EmpowHer,
I would love to offer you some advice but first I will need some background information.
Have you experienced this pain before? Have you had any injuries in that area before? Do you play any sports? How long have you had the pain?
All these factors will help us determine the cause.
Faith