Help! drug test tomorrow

I am 23 6'3" 210 lbs. I have a urine test tomorrow for a job. Last time I smoked was before Christmas. Smoked probably 5 times the 2 weeks before, and not heavily. Before that I hadn't smoked since mid November. I was habitual about this time last year.

I passed and at home test but those are only 50 mg/ml and I'm pretty sure the one I'm taking is 15 ng/ml bc they are sending it to a lab.

Am I freaking out for no reason?

Thanks in advanced