Fertility Tracking Basics: Trying to Conceive

6 Day Fertile Window: Getting the Timing Right as You Try to Conceive

Trying to get pregnant? The best time to try and conceive is during the ‘fertile window’ of the menstrual cycle. Among healthy women trying to conceive, nearly all pregnancies can be attributed to intercourse during a six-day period ending on the day of ovulation.

These six days are the ‘fertile window’ in a woman’s cycle, and reflect the lifespan of sperm (5 days) and the lifespan of the ovum (24 hours). The likelihood of actually becoming pregnant is dramatically increased if you have intercourse in the three days leading up to and including ovulation. If a woman has sex on any of these three days, she has a 27-33% chance of becoming pregnant.

Wilcox, A.J. et al. NEJM (1995) 333:1517

Tracking Your Cervical Mucus

The cervical mucus method involves recognizing changes in the mucus produced by the cervix and in how the mucus looks and feels. Just before ovulation, the amount of mucus made by the cervix noticeably increases, and the mucus becomes thin and slippery. Just after ovulation, the amount of mucus decreases, and it becomes thicker and less noticeable.

To promote pregnancy, you should have intercourse every day or every other day when the thin and slippery cervical mucus is present.

When using methods that rely on cervical mucus, be aware of any changes in your health or daily routine that could make reading the signs of ovulation difficult. Medications, feminine hygiene products, douching, sexual intercourse, or having a pelvic exam in which lubrication is used all can change how the cervical mucus appears.

The American Congress of Obstetricians and Gynecologists

Taking Your Basal Body Temperature (BBT)

The BBT is your body’s temperature when you are fully at rest. In most women, the body’s normal temperature increases slightly during ovulation (0.5–1°F) and remains high until the end of the menstrual cycle.

The most fertile days are the 2–3 days before this increase in temperature. To monitor your BBT, take your temperature every morning after waking up, before any activity, getting out of bed, or having anything to eat or drink. Record these temperatures daily.

BBT by itself is not a good way to promote pregnancy. It shows only when ovulation has already occurred, not when it is going to occur. Also, keep in mind that if you have a fever (for example, if you have an ongoing medical condition or if you get sick with the flu), the BBT method may not be reliable.

The American Congress of Obstetricians and Gynecologists

Tracking Your Cervix Position

Some women find that monitoring changes directly at the cervix gives additional supportive information about when you’re ovulating.

It generally takes two or three cycles for cervical changes to be interpreted accurately.

  • During the infertile phases of the cycle, the cervix is low in the vagina, and easily within reach of the fingertip.
    • It appears to be long and may be off-center, tilted, to lie against the vaginal wall.
    • It will feel firm, like the tip of a nose.
    • The cervical opening will be closed, giving the sensation of a dimple to the touch, and it will feel dry.
  • As ovulation approaches, the rising estrogen levels cause the cervix to rise higher in the vagina.
    • It appears shorter, straighter and more centrally positioned in the vagina.
    • It may be difficult to reach. It will feel softer, more like the texture of the lower lip.
    • The cervix relaxes slightly allowing the cervical opening to open enough to admit the finger-tip.
    • It will feel wet and flowing with mucus.
  • Following ovulation, the cervix returns to its infertile state within 24-48 hours.

Fertility UK

What is the Sympto-Thermal method?

The sympto-thermal method is a combination of methods. The two most commonly used are the Basal Body Temperature (BBT) method and the Cervical Mucus method.

The American Congress of Obstetricians and Gynecologists

The information and reference materials contained in Sprout Fertility & Period Tracker are intended solely for the general information of the User. If you have persistent general health problems or if you have specific questions, please consult your health care provider. 

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