Well if you took it and it was your first piss of the day that is probabley why it came up postitive. You urine was in your bladder all night and had time to just sit there and absorb all kinds of shit. That is the worse time to piss is if its your first piss of the day. Drink lots of water and some gatorade if your worried about your piss being too clear. When you start to piss catch it mid stream. So what you do is piss a little in the toliet than catch some in the cup and then when you get enough in the cup piss the rest in the toilet. Try not to get your first and last part of your piss just the middle. You should be fine though. Just make sure you piss a few times before you go take the test.