Personally, I hate Polygraph tests. I think it is junk science. If the operator is a good interrogator, then the polygraph is very useful as a mind game. If you are a good interrogator, you will lead the subject to believe that you already 'know' things. The problem is, if they ask you about drugs, you may call up a memory of being around them - or something happened to a friend with drugs - and that causes a physiological response. If the interrogator isn't very good, they may read the machine like it was a deception.
I went to an Interrogator School taught by this FBI guy. He called one of the class up and hooked them up to a series of wires and stuff then asked him a series of questions after explaining that they were hooked up to a 'special' FBI machine that detects lies. Due to the nature of the machine, we couldn't see it. Then he started asking all these tough questions that freaked the guy out. After he was done, the guy hooked up was sweating. He then showed us that the wires were not hooked up to anything. The power of perception is very powerful.
I certainly don't mean to insult the operators of the Polygraph. There are just as many who believe in the 'science' as those who do not. I just think that a good interrogator can do the same job without relying on a machine. If you get someone who leans too heavily on the machine, you are screwed.
If you didn't lie or try to be deceptive, don't worry about it. If it is meant to be, it will happen.
Good luck!
For me, before there was the Thin Blue Line, there was the Blood Stripe! Semper Fi!
Our fear reminds us that we are not God, our faith reminds us that He is!
**DISCLAIMER** I'm not a current LEO, but have six years experience with two city PD's in NC and TX as a sworn officer. I'm in the process of returning to LEO work ASAP.