Is it possible that I can use the excuse that I've been bulking up on creatine? I'm a big muscular guy. And they wouldn't know what I looked like a year ago. And given my bulk, excessive creatine could be an explanation on how I that big.

And to clarify my question, I was more looking for an answer that the testing center will have a more elaborate testing kit for my urine. Lets say I'm clean with the test kit I have with my test run, even with my usage, as you said, dilution might not work. And I follow the same process the day of the testing. Because of their better testing methods, would it still come up dirty? Basically, if I put a cup of warm water in the testing strip, would it come back negative or N/A?

As for the adulteration kit, I'm not sure I will have time to get, since it is the weekend, an Monday is a holiday.