Trust me I have googled my heart out but i just couldn't find the info I needed. I took two pregnancy test and both showed negative in the time frame. I left it on the counter went back later and there was a pregnant line. I know I'm not pregnant it was a clear evap since I waited so long. Can evap lines very in intensity by day? I have experienced two of what I believe to be evap lines but one was way darker than the other. Why is that?