Clearblue pregnancy test has me confused?

i took a clearblue pregnancy test last week and got a faint +. i took the 2nd one today and got a - . i took the test apart and dabbed some urine on it like 3 hours later on it. i started getting a really light blue + . i dont know what to think!! the + is invisible and is light. i can see it better when im standing in the light. where im at now, its dim lighting. should i just go to a dollar store and buy a test or am i not preggy