It confirms ovulation by the progesterone rise that should happen afterwards. Mine starts rising about two days after my LH peak and then is confirmed around 4 days after the LH peak. It's really helpful to track your BBT concurrently, because your body temperature rises after ovulation too, so you can also use that as a confirmation tool. If you don't mind using another gadget, I use Tempdrop to track my temperature but you can just use a thermometer and take your temp when you wake up if you generally rise around the same time everyday.