What happen's if I fail?

This would be my first drug test for a job ever and i'm worried about what would happen if I fail it? I'm 18, smoked Monday, and am currently on detox pills and eating red meat (I plan to try and dillute for the test). I dont know when the test will be but most likely it will be soon. It's just a pre-employment tests at a Fry's Electronics store though but I dont know. Would they just not call me back or would i get a call from some doctor or something? Also, I wouldn't think so, but could the police or anything government related get involved? I'd prefer to pass or fail without my parents knowing. I know I'm probably worrying too much but i'd just like to know, any help is appreciated.

Being a non-dot type job they just won't call if you test positive. Unless they are nice and ask you about it. And no the cops won't be called.

And your 18, why are your parents involved?