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How to chart your fertility

For many women, trying to get pregnant begins with a wait-and-see approach to sex. For others, charting their monthly menstrual cycles is the first step in the journey to parenthood. Here, Dr. Melissa Esposito, a board-certified reproductive endocrinologist at Shady Grove Fertility Center in the Washington/Baltimore metro area, answers your questions about charting.

Whether your period has been regular since you were a teenager, or you’ve never paid much attention to that time of the month, getting in tune with your menstrual cycle is essential when trying to get pregnant.

So, what’s up with my cycle, anyway?

Despite what health class may have implied, 28 is not the magic number for all women. To figure out your most fertile days, Esposito suggests this calculation:

“The first day of bleeding is considered to be Cycle Day 1, and the length of the cycle is from Cycle Day 1 to the next Cycle Day 1 of the subsequent cycle. In general, for women with regular cycles, the second half of the cycle — called the luteal phase — should always be 14 days long. So, in order to figure out when a woman is ovulating, she need only subtract 14 from her total cycle length to get her day of ovulation — i.e., a woman with a 30-day cycle would subtract 14 from 30, resulting in a Cycle Day 16 as the likely day of ovulation.”

Get a customized ovulation calendar >>

How do I chart my cycle?

One option for charting is to keep a close eye on cervical mucus. The amount and consistency of mucus changes throughout your cycle — typically dry for the first few days after your period, then slippery like egg whites during ovulation. Look for changes throughout the month when going to the bathroom; you’ll be able to notice the mucus on toilet paper.

Another option is to measure basal body temperature. Esposito explains:

“After ovulation, the body temperature rises by about one degree; if a woman becomes pregnant, the body temperature stays up, which is due to progesterone. So upon awakening and before any activity, the woman takes her temperature first thing in the morning with a special basal body temperature thermometer. She does this daily and records the temperatures. There tends to be a correlation between the dip in the temperature — seen as mid cycle — and the LH surge (LH is the hormone causing release of the egg from the follicle at the time of ovulation), but this timing is only accurate to within two or three days. The LH surge usually occurs 24 to 36 hours prior to ovulation. The dip in temperature is believed to represent the beginning of the LH surge.”

Printable basal body temperature chart >>

Do over-the-counter ovulation predictor kits (OPKs) really work?

Esposito says an OPK can be a very helpful tool in determining ovulation and timing intercourse appropriately. “The OPKs detect LH hormone in the urine — which is usually detected around 12 hours after it is detected in the blood,” she explains. “This generally means that the female will be ovulating in about 24 to 36 hours. If the kit turns positive, the LH hormone has been detected, so ovulation is going to occur, and the couple should have intercourse so that the sperm can be waiting for the egg in the tube where fertilization occurs.”

What if I have an irregular cycle?

“For the basal body temperature tracking method to be an effective and reliable way to determine ovulation, the woman must have near-perfect cycle regularity,” says Esposito. “An increase in temperature is not noted until two days after the LH peak. If the woman can figure out from the charts when ovulation is occurring, then she should time intercourse about four days prior to and two days after ovulation, every other day.”

“If a woman does not have a regular cycle menstrual cycles then menstrual cycle, charting will likely not be very helpful,” explains Esposito. “Typically, irregular cycles indicate that a woman is not ovulating regularly. So, I would counsel such women to seek a fertility specialist’s help sooner rather than later.”

Depending on your situation, a fertility specialist may prescribe medications such as Clomid or injections to stimulate your ovaries to ovulate.

Is charting a foolproof way to tell when I’m fertile?

Even if your cycles are regular, charting is no guarantee about when you’re most likely to get pregnant.

When should I consult a fertility specialist?

Esposito recommends a consultation if you’ve been trying to get pregnant for more than a year, or more than six months if you’re 35 years old or older.

Once I’ve had a baby, Is charting an effective way to avoid pregnancy?

“It most certainly is nota reliable method of avoiding pregnancy,” says Esposito. Talk to your OB or midwife about birth control options you can use until you’re ready for another baby.

The bottom line

Whatever approaches you take to conceiving, remember that no two journeys to parenthood are exactly the same. Choose the options that are best for you, and be open to talking with a fertility specialist if needed.

Don’t forget to check out our customized pregnancy calendar, which allows you to track your pregnancy and appointments, and even includes a journal to help you record your thoughts during this special time.

For more about fertility and conception

10 Ways to increase your chances of conception
10 fertility-boosting tricks to get pregnant
More articles about fertility and trying to conceive

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