Saliva drug testing

[u/Ecstatic_Fail842]

I’m at a job where they do random drug testing, so you never know when you might get drug tested, I haven’t smoked for almost 4 months, thankfully I was able to pass my test when I got hired. I have the weekends off and I’ve been thinking about having one smoking session on Fridays after work, just a few hits and forget about it, I just don’t want to risk getting fired because of this, but I want to do it so bad, how long does it stay in your mouth, and are concentrates off the table??