Contact only for positive result?

Hello, so I've been lurking and haven't exactly found the answer to my question so if anyone can possibly point me in the right direction.

Long story short I took a urine drug screen for pre-employment. Everything I read basically said "no news is good news". I didn't hear anything for 5 business days. I heard that typically its 5-7 business days for results. (Labcorp)

I told my current manager on the 6th business day I was extended an offer for employment else where and that I wanted to accept the offer but unsure of the start date. (Since I haven't had 100% certainty) but gave him a rough estimate of when that day would be.

I got a missed call from the MRO at the freaking end of the business day after I already told my current manager!

**Grumble**

And of course being the end of the business day and working full time, by the time I noticed the missed call and called the office back, they were closed. Blast FL time zone. hehe

Anyway, I'm going to call to see what's up soon, hoping their office will be open.

But between now & then, has anyone heard of a MRO making contact for just an inconclusive negative dilute? Or do they strictly call on only positive results?

It depends on what they found. If the MRO called you then it means that something showed up, maybe prescription drugs. As long as you've got a prescription you're fine.