Babytoon don't be offended, but the girls in here are either ttc or have babies on the way, or young children , all bar a few.
A lot of people register to this site and then make one or two posts to which the answer should be plain and simple and then disappear, I believe the girls read a lot of these posts and sigh.
although you say you can read etc and fair enough, as the replies were not saying anything like that, but many people do not read the instructions and it was you who made the post after all. This site consists mostly mostly of our opinions and when asked we give it freely.
It would be unlikely to change the result of a test by using it again, as there is a line of re-agent in the first half. You dip the stick, the urine wets the dye(re-agent) and then if hcg is present the dye will stain the first block(pregnant line) either way the second block (test working line) will be stained. It is becuse there is no dye left that you should'nt re-use the test, it may well have ben a fluke or because a negative test can show a positive if left for more than 10mins, while a positive result will keep for up to 48hours