About A Year Ago I Woke Up With A Lot

About a year ago I woke up with a lot of knee pain and swelling as time passed my hip bone and ankle began swelling as well and as more time passed I started getting leg spasms and if I walked too much my hip bone would pop in and out to this day it is still the same I did see a doctor where I got a CBC blood test, arthritis blood test, MRI, body scan and xrays which all came back negative and clean what could it possibly be ?