What Is The Cause And Treatment For Leg Pain?

I am a 30 y/o female and have pretty bad leg pain all up and down both legs.... not everyday, but most days. I have also had 2 bouts of optic neuritis, in the last 5 years (I was pregnant both times). I have had 2MRI's, which were both unremarkable. So ma question is do you think the leg pain may related to the optic neuritis and I might be developing MS? My neurologist can't figure it out. We've tried lots of different meds, but seems as though only hydro/oxycodone touch the pain. I appreciate your thoughts on this.