I am using the Wondfos OPKs. When you teSt and you start to get a line, as you get closer to your surge wiLL the line get progressively darker and then be a positive?? Or can it be the morning you test, and there be no line, yet test in the afternoon and get an obvious positive? Somedays I would get a faint line, then the next nothing, then another faint line. It's my first cycle using them and I think it's made me more aggravated doing it then not!