I recently submitted to a preemployment polygraph with a government agency.  During the test I was told I was reacting to the question about drug use and was confronted about it.  I admitted to using marijuana twice when I was very young (before high school), although before the test began I said I had no experience with drugs.  I knew that the test was only going to cover my drug use since much after that time (which, incidently, is absolutely none) I did not see any positive reason to admit to it.  Also, since I was younger than 16, I did not have to reveal this on the SF86 questionaire.  After making this admission, the polygrapher ran a few more charts and seemed satisfied that there was nothing else on my mind.  After the last chart the polygrapher left the room to "consult with management," and suggested that they confirmed her judgement.  Additionally, the polygrapher stated that he/she didn't think I would need to come back for a second polygraph.

The question is:  will I not need to go back because this admission is likely to have ruined my chances of employment anyway?  A few of the employees there thought it wasn't a big deal, as did the psychologist who examined me.  Still, I am worried.  Should I be?  

Thanks.