from what i understand about the urine tests... you need a certain amount of the hormone in your urine before it will detect it....
this means, if it's positive, it's positive.... you're pregnant...
however
if it's negative, you may just not have enough of the hormone in your urine to detect yet... so you can very well get a negative even though you ARE pregnant...or you may not be pregnant...
the hormone appears faster in some people than in others, when i took a home test... i was only 1 day late! it was positive SO fast, i didn't have to wait the full minute that it says...
good luck! i hope you get the answer (pregnant or not) that you are hoping for!