A Guide to Female Fertility Tracking

If you're trying to conceive or avoid conceiving, knowing the ins and outs of your fertility is crucial. Here, we'll help you get to know your body by explaining fertility and the various methods of tracking it.

The science of female fertility

In order for a person to become pregnant, an egg must come into contact with sperm and then implant into the uterus, a process that largely comes down to timing. Females typically release one egg per month during ovulation, usually around day 14 of the average 28-day menstrual cycle.

Sperm can live inside the cervix for five days, so there are roughly six days per cycle during which sex could result in pregnancy.

Why track fertility?

Knowing when you are ovulating and planning sex accordingly can help you optimize, or minimize, your chances of becoming pregnant. Since you can get pregnant only during a few days each month, knowing when those days are can help you with either goal.

However, fertility awareness methods alone are typically only 75 to 80 percent effective in preventing pregnancy, and should be combined with a more effective form of birth control, such as an intrauterine device (IUD), implant, oral contraception or condoms.

Physical signs of ovulation

A number of small signs can indicate ovulation. Basal body temperature (BBT)—that is, the lowest temperature of your body during rest, usually taken as you wake up—is slightly higher just after ovulation. We'll discuss this in more detail later on.

Additionally, cervical mucus discharged from the vagina changes consistency around that time. Other subtle signs of ovulation may include an increased sense of smell, breast soreness/tenderness, lower abdominal cramping, light spotting or discharge, and libido changes.

Methods for tracking fertility

There are several ways you can go about tracking your fertility. Your options include:

Tracking basal body temperature

By tracking your BBT daily, you may notice the slight rise—often around 1 degree or less Fahrenheit—that indicates you are ovulating. You'll need to invest in a special basal body thermometer, available at most pharmacies, that is more sensitive than standard devices.

You're most likely to get pregnant two to three days before your temperature peaks, and 12 to 24 hours after. Take your BBT before you get out of bed in the morning and make a note of it so you can start to predict what your basal body temperature should be.

Avoiding alcohol and smoking at night, and getting a good night's rest, promote consistent BBTs that make fertility easier to track.

Tracking cervical mucus consistency

Most women find that cervical mucus is thick and milky several days before ovulation. As the ovaries release an egg, it becomes thinner and clearer (like egg whites), indicating the period during which you are most likely to get pregnant.

Note that breastfeeding and douching can both affect cervical mucus. Douching is not recommended by gynecologists.

Ovulation predictor kits for luteinizing hormone

Every menstrual cycle, the amount of luteinizing hormone (LH) in a woman's reproductive system will spike, prompting ovulation. The release of the egg will generally occur 10 to 12 hours after LH levels peak. Luteinizing hormone levels will stay elevated for 14 to 72 hours post-ovulation.

So, you want to track fertility

More than 200 apps are available to help simplify fertility tracking, and the highest-ranking ones are all free. Natural Cycles and Dot are among the most popular apps for fertility tracking for birth control, whereas Clue and Flo are often used to increase conception odds. It's important to note that the effectiveness of these programs is up for debate by the experts: a 2018 study reported that fertility apps are only 21 percent accurate.

Using multiple tracking methods can increase your ability to accurately predict ovulation. Also, it never hurts to talk to your doctor to make sure you're tracking correctly as they may have additional suggestions.