hello and welcome to NT.
a dx of MS can be frightening. what helped me was to read about and get educated. the knowledge helped me feel in control and made it easier to make decisions (like about meds).

i was initially dx'd without an LP. on neuro exam and mri alone. shortly after that my neuro wanted an LP and i agreed. i had mine at the hospital under something called floroscopy. it tells the dr where the needle is.

you've gotten all good advice. staying hydrated and laying flat is important.
mine went well. my pain was minimal and i didn't have any adverse side effects. i did have 2 O-bands which clinch the dx of MS.

good luck. keep us posted.

I'm another person who had a totally benign lumbar puncture. No pain. And not even the warned-of headache. My neurologist was very good, and did the procedure himself.

I have porphyria too, and it was dx'd some time after MS. It is possible for Porph to cause demyelinization, although rare. I believe that porph can actually set an MS situation going.
I may be the only one who thinks that, but then, hardly anyone knows or even talks about porphyria.
When you get into these strange diagnostic worlds, there will be confusion. Incidentally, I recommend the Swank diet should be tried--the very low saturated fat diet. Look it up, and blessings to you.