I tested positive for methamphetamines on a urine quickscreen?

My employer has sent it to a third party laboratory for the result to be confirmed. I HAVE NEVER EVER EVER even once in my live EVER done meth of any kind!!!!!!!! The only meds i take regularly are Afrin and Zantac!!!!! What should i expect now??? They told me it takes 24-72 hrs to get the confirmed result! I could totally lose my job over this and i'm totally INNOCENT!!!! Help me please!!
allow me to reiterate--the quickscreen was a urine dipstick done right in front of me. the urine was sent to an outside lab to test specifically for methamphetamine. what i've read online is that the more specific lab ran test will be able to differentiate from any substances that are in my urine (i.e. the Afrin) from actual meth. Any truth to this??? it makes sense to me

: http://alcoholdrugstreatment.info/i-tested-positive-for-methamphetamines-on-a-urine-quickscreen