had implant out week and a half ago, bought some opks today and tested this evening....test line was very very faint which kit says is a negative? In other peoples experience do faint lines often follow or precede strong positives? I am mainly wondering because obviously having just had implant out I have no idea what cycle is doing plus at weekend had an episode of cramping/stabbing pain which I thought may be ovulation.
Afternoon is best, apparently the LH surge often happens in the morning and takes a few hours to show up in urine. OPKs test for a hormone called LH, this is present in your body all month long but peaks at ovulation. Therefore you will often see a faint line because you always have some LH in your body. That's why it is a negative result if the test line is not at least as dark as the control line.
I followed the instructions the first time I used them and tested in the afternoon and got nothing, then I discovered super cheap OPK's on Amazon (25 for 5) and started testing twice a day, once in the morning and once in the afternoon. The first time I got a positive it was in the morning but gone by the afternoon, so if I had only done afternoon testing I would have missed it. Now I only test in the morning. I am guessing all womens bodies are different, you might need to experiment a bit till you find when is the best time to test.