In reality, cycles vary tremendously among women and often within each woman herself, though most cycle lengths are 24 to 36 days. The myth of Day 14 can affect individuals in the most astounding ways:

Ilene and Mick were virgins when they got married on May 21. They wanted to start a family soon after their wedding, so they had their joint medical insurance start on May 15. When they discovered that Ilene had gotten pregnant on their honeymoon, they were pleasantly surprised that it happened so fast. Imagine their shock when the insurance company refused to cover the pregnancy and delivery, claiming that since her last period started on April 19, she must have gotten pregnant about three weeks before the wedding.

"That's impossible," she insisted. "We were both virgins until our wedding day." She tried to explain to them that her cycles had become quite long and irregular since she started jogging and dieting in order to be a "picturesque bride."

The insurance company wouldn't hear of it. They adhered to the frequently used pregnancy wheel, the calculating device that doctors rely on to determine a woman's due date. It is based on the assumption that ovulation always occurs on Day 14. As Ilene lamented, "We were sunk. How does one prove virginity in a courtroom? And why should it be anyone else's business?" Needless to say, the Day 14 myth had very expensive consequences for Ilene and Mick. The only consolation they took from their experience was the fact that their son was born just when they expected, three weeks after the insurance company 's due date! He was, in the words of Ilene, "worth all the trouble anyway."

Luckily, with advances in our understanding of human reproduction, we now have a highly accurate and effective method of identifying the woman's fertile phase: The Fertility Awareness Method (FAM). Fertility Awareness is simply a means of understanding human reproduction. It is based on the observation and charting of scientifically proven fertility signs that determine whether or not a woman is fertile on any given day. The three primary fertility signs are waking temperature, cervical fluid, and cervical position (the last one being an optional sign that simply corroborates the first two). FAM is an empowering method of natural birth control or pregnancy achievement, and it is an excellent tool for assessing gynecological problems and understanding your body

Why the Fertility Awareness Method is Not Better Known?
As you read in the introduction, probably the greatest resistance to the acceptance of FAM has been its dubious misassociation with the Rhythm Method. Unfortunately, just the phrases "Natural Birth Control" or "Fertility Awareness" inevitably conjure up jokes along the lines of "What do you call Rhythm Method users?" -- "Parents." Given the prevalence of this type of joke and the confusion of Rhythm with Fertility Awareness, is it any wonder that FAM is so misunderstood?

Furthermore, because the Rhythm Method is still practiced by people morally opposed to artificial methods of birth control, FAM tends to be falsely perceived as used only by such individuals. But in fact women from all over the world have been drawn to FAM simply because it is free of the chemicals associated with hormonal methods such as the Pill. Just as important, it allows them to minimize the time they need to use the devices that make other methods unpleasant, impractical, or unspontaneous. Many of these people tend to be oriented toward leading a natural and health-conscious life in other ways besides taking control of their fertility and reproduction.

It is true that many religious people have discovered the benefits of Fertility Awareness, though they may technically practice "Natural Family Planning" (NFP). The primary distinction between FAM and NFP is that those who use NFP choose to abstain rather than use barrier methods of contraception during the woman's fertile phase. But regardless of the differing values that often divide users of FAM and NFP all are drawn by the desire for a natural method of effective contraception.

FAM's Conspicuous Absence from Medical School
If FAM has so many benefits as a method of birth control (and as an aid to pregnancy achievement, as you will later read), why, then, is it not better known? One of the most critical and mystifying reasons that people have rarely heard of it is that doctors are still seldom taught a comprehensive version of this scientific method in medical school. It is amazing to think that women who practice the Fertility Awareness Method are often more knowledgeable about their own fertility than gynecologists who are trained to be experts in female physiology!

Years ago when I taught at a women's clinic, the entire staff except one doctor took my seminar to use FAM as a method of contraception. One day, the one who had never attended pulled me aside and whispered, "Toni, I'll be honest with you. I don't refer my patients to your classes." "Oh really, why is that?" I casually asked, trying not to act surprised. "I got pregnant using your method and haven't trusted it since," she replied. "You're kidding! What rules did you use?"

(Excerpted with permission by Harpercollins from Taking Charge of Your Fertility: The Definitive Guide to Natural Birth Control, Pregnancy Achievement, and Reproductive Health by Toni Weschler, MPH, revised edition, copyright 2001)

Want to read more?

• Taking Charge of Your Fertility is available in most bookstores, and online.
• Planning to Conceive: How to Improve Your Odds
• The Art of Tracking Your Fertility
• The Art and Science of Child Spacing