How close do they listen for PE drug test? Can you put the sample cup down?

Test is tomorrow morning (I figured get it over with)
I am subbing, and believe to have the temperature situation under control.

I know I am just freaking myself, but I am using a 3oz bottle, once emptied putting the cap and bottle back in the boxer briefs, but I am worried about shuffling and putting the cup down a couple times.

Can they just come in if they suspect? Do they knock?

I am practicing the whole deal, but I am worried about my timing with the sample transfer and me peeing in the toilet.
Do they get suspicious if you just dump the sample and they hear no peeing? I don't want to sit there with a cooling sample, waiting to nervously pee.

Thanks in advance

i think it all depends on where you are and what facility you goto... i had mine done 5days ago. i went into the restroom (where the toilet is) and the guy thats watching me held the door open and i dont know if he was watching but i he couldve if he wanted to