It depends really, did you get given a target to lose or are you just expecting to have lost?
They make not look too favourably on it if you were given a target but if you have stuck to it and you are concerned give the team a ring.
I didnt lose an ounce on my pre op diet, stuck to it 100% too. My liver was nice and small though for the op which was the purpose of my pre op diet!
Good luck!