Just wait.

Might I recommend a bowl to calm your nerves? j/k

Dont give them any reason to be suspicious. Its possible its caught up amoungst alot of other lab work, or any other number of things.

If you look act like you belong, people will usually think you belong. Dont act suspicious, dont act like you need to know if you passed. You want them to think that you know you passed, because you havent done anything wrong. Dont give them any other impression. =)