What Causes Knee Pain After Medication For Kidney Infection?

I am 26 5 6 110 lbs. Graduate student under immense stress... I recently was treated for a severe kidney infection that lasted over 2 weeks. After Avelox IV and oral as well as various other medications I am now experiencing severe joint pains from my sacrum down... everywhere. I ve had a kidney infection before due to a cath from being in the hospital being treated for pelvic fractures. Should I be worried? I can t find much in the literature.