I-485 and misdeamenour!! Help.

Hi. i applied. for my AOS. about a year ago. am finally gonna have my interview this month. i have a lawyer. but she doesnt live in the same state as me...i got my work permit. this past april, Now am alitte bit worried about my interview. since i have a misdeamenor case. for Prostititution back on 2009. i have the deposistion parpers ready for the interview. and the rest of the stuff for my interview.
Now do you guys think i am gonna be asked to do a waiver at the interview or not?
if so what happens if i get approvve at the interview. but still need to do a waiver how long does that process will take?.