Im in the hospital and they just asked for a urine sample.?

I just went before they asked so I have time. Anyways I was smoking marijuana yesterday. They say they do the urine sample for everyone that comes in here. I asked them what it was for and they said to check for bacteria and stuff. Will they find THC if its not a drug test? If it is, is there anything I can do to hide the thc? My options are limited cause I'm in the hospital bed right now. I am 14.