Could Stress In Calf Muscles Be The Cause For Pain In Knee Caps?

What do you think this sounds like to you I have had two drs tell me thier thoughts about this matter with my knee caps hurting and when I bend down they hurt my right over my left knee cap I have been told I have like knee caps moveing or sagging I have been told I just over use my legs and over stress my calfs which cause my knees and caps to hurt. I really dont know what to think i have had exrays nothin seems to look bad or out of placeno bones or joints out of place. Maybe I just over use my legs in standing and walking every day at work.