Urine test that says you did heroine but I don't even do drugs.

<p>I went for interview with career box and there ask me to do a drug test. I urinated in a cup and there said I tested positive for heroine. How is this possible when I don't even take drugs. I am so disturbed by this. When you don't do any drugs but been accused for doing heroine. I explained that I take vitamins and supplements and acne medications. But there still say I am doing heroine. Can some one please assist me if you had a similar problem or experience. </p>