strange munching after sterilization

Hello all,

I don't hide that I am terribly scared of my ferret and I don't know if her behaviour I can treat like a normal thing. I will try to describe everything accurately from beginning.
Luna is a very mobile ferret, curious, self-confident, everywhere is full of her..but everything changed when she had surgery (sterilization)... The vital ferret has transformed to buzzkill. I know that especially ferrets like sleeping but is it normal that Luna doesn't eat much (she only eats when I feed her) and when she finished eating she just comes back to sleeping?
I noticed also that after the sterilization she tries to crawling her stomach on the floor or just lying.. and this strange munching... One time only after gettin painkillers she wanted to play and she was like before... full of energy.
On Tuesday she had sterilization.Three days have passed, shoud I worry about these strange symptoms? 
I am totally scared she's sick!

Thanks for help,
N.

If she just had her surgery she will need time to recover she should be back to normal fuzzy in a couple more days. If she is still like this after a week I would then take her in for a check up.