Period Trackers: The Benefits of Tracking Your Menstrual Cycle, Calculating Your Period, and the Best Apps Everyday Health MenuNewslettersSearch Women's Health How to Best Track and Calculate Your Menstrual Cycle Keeping track of your period and monthly changes can aid family planning, pregnancy prevention, and general health. These apps can help. By Meryl Davids LandauMedically Reviewed by Kacy Church, MDReviewed: May 13, 2020Medically ReviewedDigital trackers may make it easier for you to learn about your gynecological health. Amanita Silvicora/Shutterstock; iStockIf you had to name the date of your last period, could you tick it off without thinking or are you like most women who would offer a blank stare? Closely tracking your menstrual cycles and other monthly changes on a regular basis has many benefits, whether you’re a woman thinking about getting pregnant, trying to prevent conception, or simply assessing your overall health. RELATED: 10 Home Remedies to Relieve Menstrual Cramps “Charting your cycle is empowering and fascinating,” says Toni Weschler, MPH, the author of the classic book Taking Charge of Your Fertility. “It is so much more than just a method of both natural birth control and pregnancy achievement. It’s also an excellent tool for assessing gynecological problems and understanding your sexuality and body.” Keep a Record of Your Periods Tracking your menstrual cycle simply means keeping a record of when you’re menstruating and documenting other information related to your cycle. You used to have to do this with a calendar and pen, but now many great period-tracking apps make the job easy. If you prefer to calculate your period the old-fashioned way, you’ll want to mark on a calendar the first day of bleeding with, for example, a slash or check mark, says Marjan Attaran, MD, an obstetrician-gynecologist at the Cleveland Clinic in Ohio. The length of your cycle is measured from that day to the first day of your next period, Dr. Attaran explains. For most women, the average cycle is 28 days, although anything from 21 to 35 days is considered normal in adult women. RELATED: Is It Safe to Have Sex During Your Period? Tracking Menstruation How It Helps Your Reproductive Health Knowing your cycle length is beneficial for a number of reasons. For women trying to conceive, understanding the timing of your cycle is valuable for determining the time you are most likely to get pregnant. Women are considered fertile when an egg has been released from the ovaries and is able to be joined by a man’s sperm. Because of how long both the egg and the sperm survive inside a woman’s fallopian tubes, the American College of Obstetricians and Gynecology says you can become pregnant if you have sex anywhere from five days before ovulation until one day after. Generally, ovulation is said to occur about 14 days before the start of your next menstrual period. But every woman and every cycle are different. Knowing when you might really be ovulating and having intercourse around that time can enhance your odds of getting pregnant. RELATED: National Period Day Is October 19 Charting Additional Measures Leads to Greater Success Weschler cautions that monitoring only the timing of your menstrual cycle, as some apps do, doesn’t give you enough information to accurately predict your future ovulation. The most accurate tracking apps include additional markers like basal body temperature (BBT), changes in cervical fluid, ovulatory pain, and the like, she says. In addition to period-tracking apps, a good way to monitor ovulation is with an ovulation predictor kit, which you can buy in the drug store. This uses hormones to most accurately tell you when you have ovulated. How Tracking Helps You Avoid Pregnancy For women trying to avoid pregnancy who have very regular cycles, the fertility awareness method (FAM) is used by some women as a means of birth control. The idea is to avoid sex during the time in your cycle when you are most likely to conceive. However, Attaran cautions, this isn’t foolproof and “will definitely not work for people who have irregular periods.” For these reasons, it is not recommended as a way of preventing pregnancy, she says. RELATED: Real Women Tout Their Go-To Period Products Trackers Are Not a Foolproof Way of Preventing Pregnancy “As the technology stands now, tracking should never be used as a sole method of birth control,” Weschler says, including with her own app, OvaGraph. This is because so many factors influence ovulation from one month to the next. A study published online in July 2019 in the journal Nature Digital Medicine found that women using tracking apps find they often do not ovulate at the exact midpoint of their cycle. Other research presented at a technology conference in May 2017 found that, when writing their reviews of the tracking app they used, women often cited unhappiness with inaccurate predictions. The scientists speculate this may be because the app didn’t account for factors that can throw off your cycle, like recently giving birth or approaching menopause. So while an article published in March 2016 in Global Health: Science and Practice called FAM an effective modern contraceptive, other experts point out that the method has a much lower effectiveness rate than the most reliable methods, such as intrauterine devices or contraceptive implants. In fact, the Department of Health and Human Services says about 25 percent of couples who use FAM may become pregnant. Because it is difficult to know exactly when you ovulate, to most successfully prevent pregnancy it is best to use an additional type of birth control, even if you are closely monitoring your periods. Other Reasons Period Tracking Is Helpful In addition to fertility concerns, charting your menstrual cycle is a good way to identify other gynecological health issues you may not be aware of, Weschler says. For example, a change in your cycle might suggest that you have fibroids, a vaginal infection, pelvic inflammatory disease, or endometriosis. In rare cases, it can be a flag for endometrial cancer. Tracking what happens in your body each month also helps your doctor diagnose the reason you are not getting pregnant when you want to, since it can reveal if you are not ovulating, if you are having a short second part (luteal phase) of your cycle, or even if you have polycystic ovary syndrome or another hormone imbalance, Weschler says. What’s more, tracking problems with your period is important because bad periods are not something you need to suffer through. If the next time you see your doctor you point out painful cramps or long bleeding days you have tracked, they may be able to suggest lifestyle changes or medicines to make things better for you. Finally, tracking your period can help you plan your life. Knowing when to expect your period means you won’t be caught without sanitary products or in your nicest white pants. It can also help you decide the best days to go on vacation or host that party, when you won’t be suffering from cramps. How to Calculate Your Period Accurately The best way to track your period really means the best way for you. This partly depends on what you want the information for and on your personal preference for an app’s function and design. Tracking your monthly cycle to try to get pregnant, for example, requires different features than if you want to assess your PMS. And whether you love or hate designs that go all feminine with pink colors and lots of curlicues is a matter of taste. Potential Downsides to Using Period-Tracking Apps Some privacy advocates have raised concerns about all the data you input in a period tracker and the potential for that data to be misused. Consumer Reports notes that period-tracking apps gather a lot of intimate information — about your sex life, whether you are trying to have a baby, if you engage in unprotected sex, have experienced a miscarriage, are approaching menopause — that could potentially be sold to third parties for marketing or other purposes. Having your personal health information out there may have serious repercussions, Consumer Reports cautions, such as whether and how much you pay for life insurance, or whether your employer discriminates against you. If an app lets you opt out of sharing your data (typically buried in the fine print), always do so, Consumer Reports says. The Best Period-Tracker Tools and Apps Fortunately, there are many tools available to help you track your periods. Everyday Health examined a number of them and selected some favorites. Spot On From Planned Parenthood Best For Monitoring all forms of birth control and identifying menstrual symptoms What It Does If you miss a birth control pill or don’t know when your next Depo-Provera shot is due, this app not only reminds you, it helps you figure out when backup methods are required if you get off course. Since the app is from Planned Parenthood, the comprehensive birth control info is top-notch. The app also lets you comprehensively track changes in your body and mood to better understand what affects your cycle. Bonus: This app doesn’t make assumptions about your sexual orientation or gender identity. OvaGraph Best For Trying to conceive and also intimately understanding your body What It Does Available as an app or on your computer, Weschler’s program is a comprehensive approach for tracking all your natural signs of fertility: basal body temperature, cervical mucus, cervical position, vaginal sensations, menstrual cycle timing, and more. All of this gives you the best odds of correctly determining your date of ovulation. With this program, you also get support from an active community of women and trained moderators who can answer any question you have. Natural Cycles Best For Using for birth control or a means of contraception What It Does This digital birth control method was cleared by the Food and Drug Administration as a form of contraception in 2018. You take your temperature when you wake up each morning, and the app indicates whether your BBT makes you likely to conceive (indicated in red) or not (green). The company claims the app is 93 percent effective as birth control with typical use, but this still leaves 7 out of 100 women with a potentially unwanted pregnancy. Flo Best For Predicting your period What It Does One of the most popular period trackers, Flo gives you the option to log dozens of symptoms and activities — your sleep, how much water you’re drinking, discharge color, and more — to home in on when your period (and ovulation) should come next. A selection of articles by experts can answer most of your questions, but if you have a concern you can't find covered there, you can ask anonymous questions to the app's millions of users and see what they say. MyFlo Best For Looking for holistic ways to balance fluctuating hormones, especially for women in perimenopause What It Does Under the premise that where you are in your cycle affects so many things in your life, including your skin, bloating, sleep, cravings, and more, this app takes the symptoms you record and provides the ways changing your lifestyle can help. Some of the holistic suggestions the app offers are around eating whole foods, taking certain supplements, and exercising or doing other activities — all tailored to the phase of your cycle. The app was created by a woman who found her own holistic help after years of battling hormone demons. Clue Best For Learning about your body What It Does More than 30 optional tracking categories (including BBT, cervical fluid, even what’s up with your hair) help you keep tabs on your upcoming period, your birth control method, period symptoms, and more. This very popular tracking app is also chock-full of health articles on what’s going on with your body as you go through the month, giving you an education that sex ed likely never did. NEWSLETTERS Sign up for our Women' s Health Newsletter SubscribeBy subscribing you agree to the Terms of Use and Privacy Policy. The Latest in Women' s Health Women s Health Worsened in 2021 as Many Women Lack Access to Health Screenings and Preventive Care New global report shows that despite heavy spending, the United States lags behind other wealthy countries.By Becky UphamSeptember 27, 2022 Is This the End of Roe v Wade What Would a SCOTUS Decision Mean for Reproductive Health A draft opinion from the U.S. Supreme Court strikes down the federal right to abortion guaranteed by the 1973 decision in Roe v. 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