I've finished 2 poly's with a gov agency without failing or passing them.  The problem is because I lied but I passed the post interrogation.  The question was drug use, and the truth is I've tried it but I don't feel guilty because I regret what I did and I'll never do it again.  They want me for a third poly, I want to either confess or just cancel the appointment and forget my job opportunity.  I really don't find this to be a serious issue in my life and it's just been blown way out of proportion.  However, I will have this job if I can pass this test.  What is the best approach?  How should I deal with this?  Any comments are appreaciated.  Thanks.

If you are dealing with the NSA pricks, then forget it.
It is always best to admit nothing, and assume you
won't pass the test.  They will prey on your ignorance
and fears, so just laugh to yourself, when they start
playing "head games" with you.