Community post

When the OPK's dark it lets you know that you will ovulate in the next 24-48 hours and then your BBT will confirm this by spiking upwards :) If this results in a sticky bean, you may even notice your BBT drop briefly during implantation! Hope this helps :)

FF told me I ovulated a certain day then 5 days later it said no, you ovulated THIS day then after a few more days it said it could not detect a pattern at all, so sometimes FF is wrong. I would rely more on BBT than OPK because at times, OPK's can be difficult to read but an accurate BBT makes it crystal clear.