This is actually a very interesting question, because the answer is not intuitive. Every single woman has one day in her cycle that is more fertile than any other day, but that day is not usually the day she ovulates! How can that be? Generally speaking, your most fertile day is considered the last day that you produce fertile quality cervical fluid or have a wet vaginal sensation for any given cycle. It is called the “Peak Day,” because it denotes your peak day of fertility. But this day usually occurs a day or two before you ovulate, or occasionally on the day of ovulation itself (Unfortunately, the only way to know precisely when you ovulate would be to have an ultrasound every month-not a very practical solution).

One of the obvious drawbacks of charting the Peak Day is that you will only be able to determine it in retrospect, on the following day. This is because you can only recognize it after your cervical fluid and vaginal sensation have already begun to dry up. This concept should become intuitive fairly quickly, though. Also be aware that the Peak Day is not necessarily the day of the greatest quantity of cervical fluid. In fact, the longest stretch or greatest amount could occur a day or two before your Peak Day.