Whatever your current stage of reproductive life - from menarche to menopause -  the Billings Ovulation Method™ will help you to understand about your fertility on a daily basis.

Both clinical and laboratory studies have shown that the most fertile time in the cycle coincides with what we call the Peak - the last day of the slippery sensation at the vulva.

When fertility begins, you will notice a change in sensation at the vulva which develops over the next few days leading to the slippery sensation associated with the Peak.  Any mucus you see is likely to become thinner and clearer.  Visible signs of mucus may disappear altogether, but the sensation will still be slippery.  You may also notice that the vulva itself  becomes soft, swollen and more sensitive around this time.  The Peak is recognised in retrospect, on the next day, when the vulva is no longer slippery. 

We know from the hormonal studies of Professor James B Brown that the Peak day relates very closely to the time of ovulation. In most cycles the ovum (egg) will be released on the Peak day but, in some of your cycles, ovulation may not occur until day 1 or day 2 past the Peak.  The ovum lives for a maximum of 24-hours after being released.  Once you have recognised your Peak, you can expect to bleed 11-16 days later, provided conception has not occurred.

When the time comes and you approach menopause, your fertility will diminish and you will be able to identify this decline in the symptoms you experience.  By keeping a chart of your cycles you will be able to confidently identify your times of increasing infertility and decreasing fertility.

The chart below shows that this woman has identified her Peak day (marked with a X) on day 18.  This matches perfectly with the hormonal values confirming that, in this cycle, ovulation occurred on that day.  The oestrogen (blue line) rises as the ovum is developing in the ovary.  This coincides with the woman noticing the developing pattern of mucus indicating fertility.  The progesterone (yellow line) begins to rise when ovulation is imminent.  It is the rising progesterone which causes the abrupt change in sensation by which the woman identifies her Peak. The hormone levels were measured as part of Professor Brown's study.  You will get all the necessary information from your chart without the need for hormonal measurements.