Originally Posted by
maidentomother
No. How long your OPK stays positive has little to do with when you O.
It IS normal to have creamy CM after O, but that does NOT mean CM can't and doesn't turn creamy before. Estrogen is what causes fertile CM (watery and egg white), and estrogen levels usually peak 1-3 days BEFORE O (and you will have the most fertile CM at this time). So depending on your estrogen level in a certain cycle, your CM can turn creamy sooner or later. Regarding LH surges, they are most often 1-2 days long and O most often happens 24-36 hours after you first start to surge. Next most common is O 2 days after, and it's also possible but less likely for it to occur the same day as your first positive OPK or 3+ days later. Without temps you can only guess, but OPKs are definitely more reliable than CM for determining O.