Fertility Charting

Although many women have a menstrual period once a month and ovulate, or become most fertile, about two weeks before the onset of their period, this is not the case for all. Some women have longer intervals between periods, and this can affect the time at which they are most fertile. Your own fertility pattern is unique. It is helpful to be aware of the signs that predict the times at which you are most fertile.

Cervical mucus

The mucus that comes from your cervix varies in consistency depending on how close you are to ovulation. Measuring your cervical mucus can help you determine whether you are approaching your time of ovulation. As you approach ovulation, there is more estrogen in your system, and this causes your cervix to produce more cervical mucus. Increased estrogen as your body prepares for ovulation also causes the cervical mucus to become increasingly wet and slippery.

Generally, once your period has ended, your cervical mucus will start out dry. It will go through the following stages the closer you get to ovulation:

  • Dry: no mucus at all.
  • Sticky: glue-like, gummy, stiff, or crumbly, breaks easily, not easily stretched; may be yellowish, white, cloudy, or clear.
  • Creamy: feels like hand lotion, cream, mayonnaise, or flour/water solution; may be yellowish, white, cloudy, or clear.
  • Watery: clear and resembles water; may be stretchy. You are coming close to your most fertile time.
  • Egg white: looks like real egg white, stretchy and clear, or clear tinged with white or pink; resembles semen; easy to stretch between thumb and index finger. This is the cervical mucus that comes out when you are most fertile.
  • Spotting: pink, dark red, or brown spots that leave a small mark on underwear.
  • Menstruation: light, normal, or heavy bleeding. Always start a new chart on your first day of menstruation.

There are various ways that you can check your cervical mucus. The easiest way is by wiping your vagina with a tissue in the bathroom. What do you see on the tissue? You may also notice some mucus on your underwear. Each time you wipe, record if there is mucus, what it looks like, its colour and consistency, how much there is, and whether you can stretch it between your thumb and index finger.

You may also choose to check your cervical mucus internally by inserting two fingers in your vagina until they touch your cervix. Place each finger on either side of the cervix, press gently on the cervix, and collect the mucus by moving your fingers to the opening of the cervix. Remove your fingers. Pull your fingers apart slowly to determine the consistency of the mucus.

Your chances of getting pregnant are highest when you have intercourse just before ovulation. Start on the day you first observe fertile cervical mucus, that is, when your mucus is watery, and have intercourse every second day after that point. If you think you have determined when your date of ovulation will be, based on previous cervical mucus charting, have intercourse every day from the day before ovulation until ovulation is confirmed by a few sustained elevated temperatures.

Basal body temperature

Basal body temperature is your body temperature at rest. Basal body temperature can tell you if you have already ovulated. Ovulation usually occurs on the last day before your body temperature starts to rise. Once you have ovulated, there is a higher amount of a hormone called progesterone in your bloodstream, and this causes your basal body temperature to increase.

Recording your basal body temperature in a chart, in combination with recording your cervical mucus findings, can help you to pinpoint your times of ovulation. You can measure your basal body temperature each morning with a special thermometer from the drugstore. When checking your body temperature, follow these guidelines, as they will make your charting more simple:

  • Take your temperature in the morning before you get out of bed. Any activity can cause your body temperature to increase.
  • Take your temperature at the same time each morning.
  • Make sure you have had at least three hours of sleep before taking your temperature.
  • Record the date, time, and your temperature reading each time.
  • Also record any special circumstances, such as if you had to replace your thermometer, if you are ill, if you have experienced a change in climate or a change in room temperature.

Interesting facts about fertility charting

Once you have recorded your cervical mucus findings and basal body temperature for a few cycles, you can better predict when you will be most fertile and when ovulation will occur. You can determine the average length of time between ovulation and menstruation, and when your period will come. With this awareness, you can time when you have intercourse.

Determining the length and pattern of your cycle is also helpful for the doctor, if you seek medical attention for fertility problems. Your doctor will appreciate if you have charted for several cycles. The more information you have, the better able your doctor will be to analyze your charts and decide whether treatment is necessary. Knowledge of your cycle will also help the doctor determine the best timing for any fertility tests and medications.

Charting your cycle can also help you determine from early on whether or not you have conceived, and when your due date will be. Most doctors calculate the due date from your last menstrual period, with the assumption that most women have a 28-day cycle. However, you may not have a typical 28-day cycle. Knowing when ovulation occurred can help you more accurately determine your baby's due date.

Ovulation kits

Commercial available ovulation kits are available to help you determine when you are most likely to conceive. Ovulation kits test either your urine or saliva levels each day to measure certain hormones. The kits use this information to determine the most fertile part of your cycle and the most likely time for conception.