What Causes Severe Cramping In Legs And Back With Tingling In Face?

Hi there,in 2006 I was seven months pregnant,one day I came down with my first migraine it was the worst head pain I had ever felt.I woke up the next morning and was completley blind in my left eye my doctor treated me with B12 shots and referred me to a neurologist.A fewi days later the bottoms of my feet started to feel like the were numb and tingling, after about a week I was compltley numb from the bottoms of my feet to under my chest. At this point I could not use the washoom or walk so I went to emerg. I had an MRI done wich showed from what they told me showed bright spots on my spine and they suspected MS. After about four weeks my vision came back and I was slowly able to walk on my own again. Six months after my daugter was born I had a follow up MRI not at the same hospital where the first MRI was, that Mri found no lesions the second time around ( I don t understand what happened there) Then last year some of the numbess and tingling in my legs and hand came back but it was almost unoticeable and only last for a few weeks, my Neuro had me go for another MRI which showed 1 new lesion on my spine and they still could not positvley diagnos me with MS. Now for the last four months I have been have severe cramping in my legs and back, electric shocks in my neck and face, tingling and numbness and a few other things. Is it possible that something else is going on with me? I have been tested for so many other things and everything comes up negative. Oh I forgot to mention my vision loss in my left eye was optic neuritis I beleve of the disc.