Evidence-based · Symptothermal Method · Always Free

Know your body.
Own your cycle.

The only fertility awareness app where every charting feature is free — forever. BBT tracking, cervical mucus, OPK tests, and more. No paywalls. No algorithm deciding your fertility. Your body, your knowledge.

Cycle 4 · Day 18
Post-Peak Confirmed
Day 1 Ovulation Today
Pre-ovulatory
Post-peak
Coverline
BBT
97.8°
Mucus
Dry
OPK
Neg
Cx Pos
Low
100%
Core features
always free
0
Data sold
ever
STM
Evidence-based
symptothermal method
1
Optional paid feature
AI coaching only
💸

Other apps paywall your own data

Natural Cycles starts at $149/year. Flo locks core features behind $50/year. Clue pushes Clue Plus constantly. You shouldn't pay a subscription just to chart your temperature.

🤖

Algorithms that decide for you

Most apps replace your understanding with a red/green day verdict. That removes the knowledge — and the autonomy — that makes fertility awareness actually work.

🔒

Your intimate data isn't safe

Flo paid $90M to settle FTC charges for sharing period data with Facebook. Ovia was acquired by Labcorp. Your fertility data is more sensitive than anything else on your phone.

The honest comparison

See what others charge for

Every feature below is free in Fertility Awareness. Competitors charge $50–$150/year for the same tools. The only thing we charge for is optional AI coaching.

Feature Fertility Awareness ✦ Natural Cycles Flo Clue Kindara Read Your Body
BBT charting Free ~ Paid only ~ Limited free ~ Plus only Free Paid
Cervical mucus tracking Free ~ Paid only Free Free Free Paid
Cervical position Free Free Paid
OPK / Pregnancy test logging Free Free ~ Limited Free Paid
Spotting vs. period distinction Free ~ Limited Free Paid
Travel / sick / alcohol flags Free ~ Sick only Free Paid
Symptom severity levels Free ~ Plus only ~ Plus only Paid
User interprets their own chart Always Algorithm decides Algorithm decides Algorithm decides Always Always
AI coaching / guidance Optional add-on ~ AI chatbot (paid)
Data privacy model Your data, no selling GDPR compliant FTC settlement 2021 Berlin, GDPR native Standard Device-only option
Starting price $0 forever $149.99/year $49.99/year ~$25/year $49.99/year $20.99/year
What's included, free

Every tool you need to
practice true FAM

The symptothermal method works by combining multiple fertility biomarkers. We track all of them — without charging you for the ones that matter most.

🌡️

Basal Body Temperature Charting

Log your waking temperature each morning, see your coverline auto-calculated, and track the thermal shift that confirms ovulation. Works with any basal thermometer.

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Cervical Mucus & Position

Log mucus observations with the detail they deserve — type, sensation, color — plus cervical position and firmness. The most complete mucus tracking in the market, free.

🔬

OPK, Pregnancy & Progesterone Tests

Log LH test results, pregnancy tests, and progesterone test strips to build a complete hormonal picture alongside your physical signs.

📊

Expanded Symptom Logging with Severity

Track headaches, cramps, breast tenderness, mood, energy, and 30+ more symptoms with graduated severity — so your chart tells your full story.

✈️

Temperature Reliability Flags

Mark temperatures taken after travel, illness, alcohol, or disrupted sleep. Your chart stays honest — and you stay in control of what data you trust.

Today's Reading
97.8°F
Above coverline · Day 3 post-peak
Menstruation
Pre-ovulatory
Peak
Post-peak ← You
Mucus
Dry
Cx Pos
Low
OPK
Neg
Cycle Length
28d avg
±2d range · 6 cycles
Symptom today
Mild cramps
Good energy
Getting started

Simple to begin, meaningful over time

The symptothermal method reveals patterns your calendar never could. A few minutes each morning is all it takes.

01

Take your temperature

Each morning, before getting up, measure your waking temperature with a basal thermometer. Log it in seconds. The app builds your chart automatically.

02

Observe your signs

Log your cervical mucus observations, position if you check it, and any symptoms. Each sign adds a layer of clarity to your fertility picture.

03

Read your chart

Watch your thermal shift emerge, your mucus pattern build, and your cycle phases reveal themselves — interpreted by you, not an algorithm.

04

Deepen with AI coaching

Want a knowledgeable companion to discuss your chart? AI coaching is there when you want it — teaching you to read your own signs, not replacing your understanding.

Your data, period

We built this for
women, not advertisers

Fertility and cycle data is the most intimate information you generate. After Flo's FTC settlement and Ovia's acquisition by Labcorp, you deserve a clear answer about where your data goes.

Our answer: it stays with you. We earn revenue only through optional AI coaching subscriptions — never through data monetization, advertising, or third-party sharing.

🔐 No data selling, ever
📵 No ads, no tracking pixels
🌍 GDPR compliant
📧 Minimal data collected
🚫

Zero data monetization

Your cycle data is never sold, licensed, or shared with third parties for any commercial purpose.

💰

One honest business model

We earn from AI coaching subscriptions only. Our interests align with yours, not with advertisers.

🗑️

Delete anytime, completely

Request full account and data deletion at any time. No cooling-off period, no retention.

🔍

Transparent data practices

Clear, plain-language privacy policy. No legalese designed to obscure. You know exactly what we store.

🌱
Fertility Awareness Coach
● Online — powered by AI
My temperature dipped today on day 19. Is this normal?
That dip on day 19 is likely just normal variation — your chart shows a solid thermal shift from day 14 onward with 5 consecutive temperatures above your coverline. One dip that stays above the coverline doesn't invalidate the shift in Sensiplan guidelines. Your mucus has also been dry for 6 days, which supports post-peak interpretation. I'd call this a reliable infertile phase. Want me to walk through what would actually change this reading?
Yes please — and what should I watch for next cycle?
Great question. Here's what would affect it: a temperature below your coverline would restart your count. But given your pattern, that's unlikely. For next cycle, I'd watch your mucus onset — your Peak Day arrived 2 days before your thermal shift, which is typical. Catching Peak Day in real-time will help you feel more confident about the fertile window...
AI Coaching from $9.99/mo
Try AI Coaching →
The only paid feature

A coach who teaches, not one who decides

AI coaching fills the gap between raw charting data and true body literacy. It's the difference between knowing your temperature and understanding what it means.

Chart interpretation guidance — Get personalized explanations of your BBT patterns, mucus observations, and what they indicate within your chosen FAM method.

Cycle-aware pattern analysis — Understand your cycle's unique rhythms across months, with insights connecting your physical signs to your overall health.

Education in context — Learn the Sensiplan rules, Creighton observations, or TCOYF guidelines through questions about your own real chart — not generic explanations.

Always available, never replacing your educator — AI coaching supplements professional FAM instruction, never replaces it. It knows when to say "talk to a certified educator."

Core tracking stays free
Everything you need to chart your cycle and practice the symptothermal method is always free. AI coaching is a voluntary upgrade — never a gate on your fundamental health data.
Real stories

Women who know their cycles

From recovering from hormonal birth control to trying to conceive, fertility awareness changes the relationship women have with their own bodies.

★★★★★

"After 10 years on the pill, I didn't know what my natural cycle looked like. This app helped me chart my first real cycles with so much clarity. The BBT chart alone showed me my cycle was longer than any app had ever predicted."

S
Sofia M.
Came off BC · 8 months charting
★★★★★

"The privacy thing matters so much to me post-Dobbs. I'd stopped using Flo entirely. Finding an app that has absolutely no interest in my data beyond charging for coaching? It's honestly a relief. I can chart in peace."

A
Amara J.
Privacy advocate · TTC · 4 months
Questions

Honest answers

Fertility awareness is a serious health practice. You deserve clear, medically accurate information — not marketing fluff.

Start Free Today →
Yes. Every core charting feature — BBT, cervical mucus, cervical position, OPK logging, symptom tracking, temperature flags — is permanently free with no trial period and no expiry. AI coaching is a paid optional add-on. We will never move core charting features behind a paywall.
This app is a fertility charting tool, not a contraceptive device. The symptothermal method, when properly learned and consistently applied, has high effectiveness — but effectiveness depends on correct practice, not the app. We do not provide fertility window predictions because calendar-based estimates are not reliable. We strongly recommend studying with a certified fertility awareness educator if you intend to use FAM for contraception.
Natural Cycles charges $150/year and uses a proprietary algorithm to declare your fertility status — removing your interpretive role. Flo paid $90M to settle FTC charges for sharing user data. We charge $0 for charting, monetize only through optional AI coaching, and never touch your data for commercial purposes. We also respect your autonomy: you interpret your chart. The app gives you the tools; you apply the method.
AI coaching lets you ask questions about your chart and get personalized, method-aware responses. It can help you understand your temperature patterns, discuss your mucus observations, explain FAM rules in context of your own cycle, and identify patterns across multiple cycles. It supplements — but never replaces — instruction from a certified fertility awareness educator.
Any basal body thermometer that reads to two decimal places (e.g., 97.84°F / 36.58°C) works well. You don't need any branded or connected thermometer. Digital oral thermometers under $15 work perfectly. Wearable BBT sensors like Tempdrop also sync directly with the app.
Yes — symptothermal method charting is actually more reliable for irregular cycles than calendar-based apps, because it works with your body's current cycle signs rather than predicting from past averages. The app handles anovulatory cycles, long cycles, short cycles, and post-pill recovery patterns accurately.

Your cycle has always
been telling you something.
Start listening.

Join women who've moved from guessing to knowing. Everything you need to practice fertility awareness is free — always.

Free forever · No credit card · No trial expiry · Works on web, iOS & Android