I have a pre-employment drug test at 8:30am on Tuesday, July 2nd and I was wondering if I could take Xxtra clean a few days before? I am a female, 5'5, 135lbs, and have smoked every night during the week and 3-4 times on weekend days for the last year and a half. I stopped on Saturday night, June 22 so that would be one week and two days away from test. Would it be a waste to take Xxtra clean days before the test? Thanks to all for your input.