Community post

We all have LH in our systems, all the time. If a woman takes an OPK its very likely for it to show some sort of line. Now, sometimes you can catch it (especially if you test 2x a day) on its way up, getting darker. When its as dark as or darker than the control line, its detected the LH surge which means ovulation will take place in the next 12-24 hours. Consider yourself fertile from the day they start getting darker, darkest and when they start getting lighter. You should experience fertile CM at this point, and if you take your temp, it should spike the day after ovulation.
So. Darkest OPK this morning would mean you will ovulate today/tomorrow (12-24 hours) and the egg sticks around for about 24 hours itself, so thats the best time TTC!

Good luck and hope this helps :)

Ok I'm an expert on OPK's lol
So when you get your first positive OPK it give you warning that you are most likely to ovulation within 12-36 hrs.
Some woman like me will get + OPK's for several days, sometimes the egg can take a bit longer to release.
For eg: when I got preg in Aug. My first positive was on cycle day 16 and they got stronger and stronger the darkest being cycle day 19. Everyone I'd different just keep having sex from the time to get your first pos until it goes to neg. Or if you want to be really sure you don't miss your surge have sex every second day from CD10-20
I alway did it from CD11-20 but I knew when I Ovulated as I can feel it.
Hope this helps. Good luck :-)

update!!

just took an OPK test just a few minutes ago and it's about the same color has yesterday (a dark line, but not "dark" like it was this morning. We dtd tonight...so I'm crossing my fingers!!!!!! :) :)

Since they explained them a bit for you Im just going to add that you should not use fmu, it can give false negatives which will make you miss your surge. And test at least 2x a day(:
gl keeping my fx'd for you