security clearance poly questions

I currently did my poly, drug test, and mental exam. On my poly i admitted to doing one puff on a dab pen which is a THC pen with flavoring similar to a vape when i was 18 i am 21 currently. It was one of those things in my life that I regretted. It was the only time in my life i have done any form of drugs. I don’t do drugs or even drink. i was just being curious. i didn’t put it in my SF 86 and in my poly i said it after when they said i was omitting something. They told me that admitting to a single instance is good so now they said it goes to quality assurance who will see if i get my clearance. What are my chances of getting my TS clearance for my job offer for Lockheed martin

hard to say… your biggest hurdle is the original lie/non-disclosure. Be prepared to answer why you did not list or disclose this on the SF86 or during your interview to review the SF86.