I'm a little nervous...!! :-/

I've been to two different facilities for the D.O.T. drug screen. Both just had a single restroom. The first facility was an old building. It had a regular restroom, but the cabinet under the sink had locks on the doors.
The last facility was pretty much tamper-proof. For urine samples, they used a restroom that just had a toilet. No sink. No cabinets. You washed your hands at the sink outside the restroom.

 

They never tested for drugs on my latest dot physical.wtf?

 

Unless the company requests a D.O.T. drug screen with your physical recertification, they won't.
Most all companies should do a pre-hire D.O.T. drug screen. After that, they usually just do random drug screens, or a post accident drug screen.
It's bad enough for a truck driver to be involved in an accident, but if you fail a post accident drug screen you are really in a world of trouble.