Hi sarah,

I've been using opk's on and off for 8 months. I've never ever been confident that I got a positive even though I definatly ovulate. The closest to it, a dark 2nd line for two days, was not technically a positive but I am sure in retrospect that it was about where I ovulated. So I always go by the darkest 2nd line result. I always have a two day fade in and fade out.
However, if I use fortel, nothing! No fade in & mostly no second line. If I get a slightly dark line it will be for a few hours and when re-testing later same day in the hope that I get a true positive, gone. Perhaps if they were cheaper I'd test more (4-5times a day?) and be able to get that elusive result but till now my affordable lullaby conception tests are the only way to go. the fade in gives you some warning that ov is coming which is nice.
It's frustrating but I hope this helps,

sassba