FERTILE FAQ

A1: A menstrual cycle and fertility tracker that runs in your browser. You log your periods, and if you want, your morning temperature, cervical mucus, ovulation test results and symptoms. The tool shows your cycle day, phase and fertile window on a dashboard and a month calendar, estimates ovulation and your next period, charts your temperatures by cycle, keeps statistics across cycles, works out a due date, and can make a read-only calendar link for your partner. Nothing is uploaded and there is no account.

A2: Nothing. There is no plan, no limit and no feature held back. Like every page on ZeroDataUpload, the tool is supported by advertising.

A3: No. There is no registration and no login. Open the page, log the first day of your last period and the dashboard fills in.

A4: Neither. It is a tracking and information tool. Its dates are estimates that can be days off, especially with irregular cycles, and it cannot tell whether an egg was released in any given cycle unless your own temperatures or tests say so. Do not rely on it to avoid pregnancy; if you want to use fertility awareness for that, learn a recognised method from a trained instructor or a doctor. Talk to a doctor about anything that worries you.

A5: Yes. The cards stack one above the other, the calendar fills the width, the log forms use the phone's date and number keyboards, and the five tabs sit in one row. Add the page to your home screen if you open it every morning.

A6: Yes. Settings, Display, Temperature unit. Readings keep the unit they were entered in and are converted for display and for the chart, so switching back and forth changes nothing you logged.

A7: From the first day of your last period, your cycle length and your luteal phase. Ovulation is estimated at cycle length minus luteal phase days after the period started (day 14 of a 28-day cycle with a 14-day luteal phase), and the fertile window runs from five days before that day to one day after, because sperm can live up to five days and the egg about one. Once you have logged two or more periods, the cycle length used is the average of your own recent cycles. A positive ovulation test or a confirmed temperature shift in the current cycle replaces the estimate for that cycle.

A8: The setting until you have logged two periods. From then on it uses the rounded average of your last six cycles, leaving out any cycle shorter than 15 or longer than 60 days as a likely gap in the log. The dashboard chip says which it is using ("Average of your last 4 cycles: 29 days" or "Using the 28-day setting"), and the Cycle setting under Settings says the same.

A9: An estimated chance of conception from intercourse on that day, taken from a study that measured day-specific chances in 221 women trying to conceive (Wilcox, Weinberg and Baird, New England Journal of Medicine, 1995): about 10% five days before ovulation, 16% and 14% on the next two days, 27% and 31% on the two days before, 33% on the day itself, and 5% the day after, which only allows for error in the ovulation estimate (the study found no pregnancies after ovulation). It is an average, not your personal odds, and it says nothing about any one cycle. Age, health and much else that a tracker cannot see change the real figure.

A10: The days from ovulation to the next period. It is fairly constant for each person, usually 12 to 14 days, while the days before ovulation vary. That is why the tool places ovulation by counting back from the next expected period rather than forward from the last one. If your temperature chart or tests confirm a few ovulations, the Cycle by Cycle table shows your real luteal length, and the Cycle Lengths card suggests changing the setting when it differs.

A11: The dashboard says "Period expected" with the date it was due and the number of days late, and keeps the current cycle open. Log the period when it starts; the real cycle length then goes into your average. Late periods are common, and the tool cannot tell you why; a pregnancy test or a doctor can.

A12: Days after today. Their colours are predictions from your cycle length and settings; past days show what was estimated or confirmed for them. The further ahead, the rougher the prediction: the next cycle's dates assume it will be exactly as long as your average.

A13: First thing in the morning, before getting up, talking, drinking or moving about, at about the same time every day, after at least three hours of sleep, with a thermometer that shows two decimals. Log it under Log, Temperature, with the time, and add a note when something could have raised it: a short night, illness, alcohol the evening before, a much later reading. Noted readings show in orange on the chart.

A14: By the three-over-six rule used in fertility awareness methods: when three temperatures in a row are higher than the highest of the six before them, by at least 0.2 degrees Fahrenheit (0.1 degrees Celsius), the tool draws a coverline and marks the shift. Ovulation most likely happened the day before the first high temperature. The rule needs at least nine readings in the cycle, six low and three high, so a chart with gaps may show no shift even when one happened.

A15: Dry (little or none, usually right after the period: low fertility), sticky (thick and paste-like: low), creamy (like lotion, white or yellowish: medium, oestrogen rising), watery (clear and wet: high, the fertile window is near) and egg white (clear, slippery and stretchy: peak, ovulation is close). The tool records what you pick and shows it on the calendar; it does not move the ovulation estimate, because mucus is a sign to read alongside the rest rather than a date.

A16: The first positive test in a cycle becomes that cycle's surge day, and ovulation is placed on the day after it, which replaces the calendar estimate for the fertile window and the next period. A confirmed temperature shift takes precedence over a test, because the test shows the surge and the temperature shows that ovulation followed. "Almost" results and the line strength are recorded for your own reading of the strip and shown on the calendar.

A17: Cramps, bloating, breast tenderness, headache, fatigue, mood swings, acne, ovulation pain, backache, nausea, high libido and insomnia, plus a free note for anything else. A day with symptoms gets a dot on the calendar, and the Cycle Lengths card notes how often ovulation pain fell within two days of the ovulation estimate.

A18: Red is a period day (a paler red for a light flow), the three greens are the fertile window from low to high chance, the deep green is the ovulation day, and a dashed edge means a predicted day in the future. Dots under the number mean something was logged for that day. Click a day to see its status, chance and everything logged.

A19: Average cycle is the mean gap between the first days of your logged periods; variation is the difference between the shortest and longest; average period is the mean number of bleeding days of the periods with an end date; regularity is 100 minus ten times the average difference of your cycles from their mean, so cycles within a day of each other score above 90. All four need at least two periods and get better with six or more.

A20: Each of your last twelve cycles with its first day, length, period length, ovulation date, how that date is known (a temperature shift, a positive test or the calendar estimate), the luteal phase for finished cycles with a confirmed ovulation, and what was logged in it. The current cycle is highlighted and shows its day instead of a length.

A21: Naegele's rule: 280 days from the first day of the last period, adjusted by the difference between your cycle length and 28 days. It also shows the likely conception date (cycle length minus 14 days after the period), how many weeks along you would be today, the trimester and the progress through 40 weeks. Only about one baby in twenty arrives on the date; an early scan gives a better estimate. It fills in from your last logged period, and you can change the dates freely.

A22: Each switched-on reminder shows at the top of Coming Up on the dashboard on its day: two days before the expected period, the day before the fertile window opens, on the ovulation day, every morning until a temperature is logged, and on each day of the fertile window until a test is logged. If you allow browser notifications, the same text also appears as a notification once a day when you open the tool. A web page cannot wake up on its own, so nothing fires while the tool is closed.

A23: The screens. With the lock on, the tool opens on a PIN prompt and shows nothing until the four digits are entered, which keeps a shared device's other users from glancing at your calendar. The PIN is stored only as a scrambled hash and cannot be recovered. It does not encrypt the stored data: anyone with full access to this browser profile could still read it. Too-easy PINs such as 1234 or four of the same digit are refused.

A24: The lock screen has one way out: Forgot it? Clear all data, which deletes everything the tool stored in this browser, the PIN included, and starts over. There is no recovery because the digits are not stored. Export a backup from time to time so a forgotten PIN costs you nothing.

A25: Under Settings, Partner Sharing, tick what to share (fertile window, ovulation day, period dates), make the link and send it however you like. The few dates needed are packed into the link itself after the # sign, so nothing is stored anywhere and the part after # is not even sent to the server when the page loads. Whoever opens it sees a read-only calendar with the coming days and a button to open their own tracker. The link shows the cycle as it was when you made it, so make a new one after logging the next period.

A26: No. The link carries only the last period's first day, your cycle settings and, if you tick period dates, the first and last days of your last six periods. No temperatures, tests, mucus, symptoms or notes ever go into it.

A27: In your browser's storage on this device, under the tool's own name: periods, temperatures, mucus, tests, symptoms and settings. Nothing is sent to a server, there is no account and no sync. Like every page on the site, the tool page shows ads through Google AdSense and uses Google Analytics; the Privacy Policy and Cookie Policy explain what those collect and how the cookie banner controls them. Your entries are never part of it.

A28: Settings, Your Data, Export backup, which writes one file. On the other computer open the tool, Import backup, choose the file and confirm; it replaces what is there. The PIN is not in the file; set it again on the new computer if you want it.

A29: One row per day that has anything logged: the date, cycle day, status and chance, whether it was a period day and the flow, the temperature with its unit and time, the mucus type, the test result and line strength, the symptoms and the notes. It opens in any spreadsheet and is the easiest thing to hand to a doctor.

A30: The Insights section: the four statistics, the temperature chart of the selected cycle, the cycle length chart and the Cycle by Cycle table, on plain paper without the rest of the page. Pick the cycle you want in the chart first.

A31: Yes, if it is the same browser and site data was not cleared. On the first visit the tool reads the old entries, checks every value, carries them over to its new storage and removes the old copies. Temperatures from the old version count as Fahrenheit, which is what it used. If the old version had PIN protection on, the same PIN works.

A32: The browser's site data was cleared, a cleaning tool removed it, you are in a private window, or you are in a different browser or profile from the one you logged in. The tool has no copy anywhere else, so the only way back is a backup file you exported. Export one now and then.

A33: The rule needs three readings in a row that are all at least 0.2 °F (0.1 °C) above the highest of the six readings before them. One high reading, two, or a rise of only one tenth of a degree is not enough, and a reading with a note counts like any other. Check for a missing morning and whether the thermometer shows two decimals.

A34: It refuses a first day in the future, a last day before the first, a period longer than 15 days and a period starting within ten days of one already logged. The last rule stops an accidental double entry; to correct an existing period, use Edit in the table beside the form.

A35: Allow them under Settings, Reminders, Allow browser notifications, and check that the browser and the system allow notifications for this site. They appear only once a day, only when a reminder is due and only when you open the tool; the tool cannot notify you while it is closed.

A36: Settings, Your Data, Clear all data, then confirm. Every period, temperature, test, symptom and setting the tool stored in this browser is removed, the PIN included. Export a backup first if you want a copy.