Benzos stay in your system for a really long time. I'm sure that's why you tested positive. 2 weeks isn't nearly long enough. I read that takes months.
I asked for a mouth swab test which came back clean. Sorry meant to add that
I had the same problem when I started at the clinic, after taking pills for so long your liver enzymes tend to get high. Which in turn makes it filter slower, I'm no doctor but this is the way I understand itn