Lumbar puncture tomorrow

Hi everyone,
I got a letter today when I got home from work telling me that my lumbar puncture/spinal tap is booked in for tomorrow, not much notice. I quickly rang a friend & she will take me in & home again too. Just hope we get a carpark easily too.
Bit nervous as I have had this before & ended upback in hospital with a migraine 2 days later when couldnt keep food or drink down.
Will be glad when its over
Bit worried about reactions
Sue