Ladies with kittens/cats........spay question

My little baby ( 7 months old) was spayed monday...i picked her up yesterday at 3PM. I only held her for about 15min total since she has been home.....she is hiding under my bed against the heater and wants nothing to do with me...I understand she is probobly inpian so im ok with that....but what i am wrried about it...she has hardly eaten or drank water since last night and she hasnt peed or pooped ....i took the littler out of the box like the vet saiod and put newspaper in it... i havent found any spots anywhree like she has gone soemwhere otehr than the litter box....i called the vet they said give it till tomorrow after work and see if she goes...she might just not have to go yet cause she isnt really eating or drinking but to keep an eye on her and if she doesnt go by tomorrow when i get home for work to call and ill have to bring her in..........did anyone have this problem with their cat???
Sorry so long....thanks in advance for any help!

Kitty Wu was the same way when we got her fixed.
She had no interest in food or water for like a day or 2 because she was in pain/uncomfortable and hid for the same amount of time.
she wasn't using the litter box either b/c she hadn't eaten or drank and she wound up being fine but I was nervous too. We brought her in for a follow up and they said she was okay. She went back to her old evil ways a few days later.

Klinger just had a surgery done a few weeks ago and he reacted the same way, not eating or drinking for 2 or 3 days and therefor not using the litter box.

i have dog litter here if you want some, it's dust free so it's fine for her stitches and everything, but has a consitancy a little more like regular litter so she may be more comfortable using the litter box with it, that's been an issue with our cats before too, the refuse to go in shredded or regular newspaper

hmm..I think i would be hiding and afraid to use the potty if i just had my ovaries ripped out of me!!

On a serious note..its totally normal...she is prob so scared to move /eat/pee/poopoo...If its more than 3 days then i would be nervous..but once she gets settled she will be fine!!