To test or not to test?

Am
I hate wasting tests. 
I just do. 
So I tested Thursday morning, first morning urine and all. It was negative.
I was supposed to get period on Saturday and I've been pretty regular. 
Maybe a day off here and there. It was a cheep dollar tree test by the way (if that matters). 
Well, still no monthly visit still. Should I waste a test? Or do you think the one from Thursday was accurate with its negative so no point in testing?