Ive seen several responses to this so it has to be possible. I was homeless, living in my car and wherever I could. My friend (?) Was doing this everyday all day with other people to. I had no where else to go. I was Broke, no license and been evicted because the girl I was seeing choked me, then called the police and I had to leave the house. It was over this time. It was like 7 to 8 months where I was in the air with that . I had a couple ua's and they where just fine then I tested positve. And the dr.s all cut me off. What can I do to challenge this? The fact I wasn't doing it, and I still tested positive.