Completely Numb from the waist down ( 8 days now )

* I also posted this on the MS section of the forum without realising, althou i have got some great help and support!

I am Male, 27 years old and a fairly active person, i don't play sports, i work as a Call centre manager and i do walk about most of the day whilst in work ( 80%)

From Wednesday (2nd April 08) i have had a numbness sensation from my waist down to my feet, and this includes all areas..
It started off with a slight pins and needles feeling in my legs, but has gradually began to get worse.
I went to my Doctor last friday the 5th April who examined me and came to the conclusion that i have a trapped nerve. And that was it - he sent me on my way and said give it a few days.
I didn't believe that a trapped nerve could cause so much uncomfort!

I have a history of blood clotting due to a blood disorder which i was diagnosed with some years back ( Factor V Leiden Mutation ) I was prescribed Warfarin which i took for a while until the Doctor said i didnt need to carry on taking them, i havent taken Warfarin for roughly 6 or 7 years now.
My last complaints of anything similar to this would have been about 4 or 5 years ago when i had a slight numbness sensation like i do now, only it wasnt half as bad and only lasted for a day and i didnt go to the dr.

I went to my hospital on Monday of my own accord and after a 3 hour wait and 30 minute of being poked with a pin the Dr was baffled - Doesnt know what's causing this, told me to Monitor myself for a week and if symptoms persist to go see my GP who will refer me to a neurologist.
He did say however should i start to get any pains in my legs or impaired vision of any sort then i should go back to casualty.

I called my Dr the next day and made another Appt, re-examination and he came to the conclusion that it's not a trapped nerve, he took blood samples which i am currently waiting results, he also mentioned that the hospital should have performed an MRI scan ( What is this for?? )

This whole experience is frightening and no one seems to have any answers, i "may" need to be referred to a neurologist if the symptoms dont go away.. even if they do i want to know why they came and how to prevent them in the future!!
I have not been ill recently and have not had any injuries at all, the only thing thats happened in my life within the last 6 months has been the death of my 6 month old nephew which was last month.
Since yesterday i feel as though its getting worse, i get random pain in both my knees and my legs feel really heavy.
My bladder and bowel are working fine apart from i can't feel myself going! As is my eye sight ( Questions i keep getting asked )

Thats all i can think off right now, any advice from a professional as to what i should do, how long should i let it go before it becomes serious and what it might be thats causing this will be greatly appreciated.

Ricky