I would recommend that you take the test. That way you know. Everyone processes THC metabolites at different rates but from your post you sound as if you may be OK depending on when your last time smoking was. The more time without smoking the better. You have the right idea by testing your morning void, if you are clean then you should be fine later in the day. 40 oz. of gatorade wouldn't hurt to be on the safe side.

As far as your paycheck question, I do not believe that the Co. can withhold your paycheck until you pass a UA also whatever your result they must pay you for your time worked. They are within their rights to terminate your employment if you do not pass their drug screen.