Ok, some advice for you.

Don't sub out someone elses urine for your own in this kind of situation. They are giving you a urine test for other reasons than screening drugs. They aren't out to get you. Besides that, the urine you sub out will not work unless it comes from a pregnant woman. Male urine is slightly different than female urine, and a woman that is pregnant will have urine slightly different than a nonpregnant woman.

Also, my mom smoked the entire time I was in her womb, and I turned out just fine. I'm a college student thats about to enter the real world. But, I definately stand up and applaud the fact that you are willing to completely clean your body up already to have this baby, great job.