HI Dr, Samuel, my name is Mike , and my drug test came back inconclusive and now they are sending my urine to a lab. However, I had a urine test done January 30 , and passed . In the time between tests , I have not taken any illegal drugs . Why could this be ? I do have brutal heartburn lately , and I ve taken acid reflex pills. I drink lots of water and coffee. I have done drugs recreationally in the past. Again, I passed my first test with the other company that was going to hire me. I watched him test with a test strip.