Step 1
Decide on contraception first
If you rely on Natural Cycles as birth control, talk to your doctor before you stop. Her Good Days can't replace it.
Natural Cycles vs Her Good Days
Her Good Days vs Natural Cycles
These two apps do different jobs. Natural Cycles is a contraceptive. Her Good Days is a free health tracker that isn't birth control.
- Checked October 30, 2026
- Every Natural Cycles fact linked to its source
Comparing more apps? See period tracker apps, compared or Natural Cycles alternatives.
Her Good Days is not birth control. Its fertile days are estimates, labeled Not birth control. Natural Cycles is cleared by the FDA as a contraceptive (De Novo DEN170052, granted August 10, 2018: FDA record).
| At a glance | Natural Cycles | Her Good Days |
|---|---|---|
| What it's for | FDA-cleared birth control from your temperature (FDA) | Tracking periods, symptoms, pregnancy and menopause. Not birth control |
| Price | $21.99 a month or $149.99 a year (App Store) | Free. No paid tier |
| Devices | Thermometer, NC° Band, Oura, WHOOP, Garmin or Apple Watch Series 8+ | Your phone; steps from Apple Health or Health Connect |
| Perimenopause | NC° Perimenopause, temperature based | Hot flashes by week, sleep next to night sweats, a doctor report |
| Verdict | Fits if you want hormone-free contraception and will measure daily | The pick if you want a free tracker and don't need contraception from an app |
Where Her Good Days is different
A tracker, not a contraceptive
Natural Cycles reads your temperature every morning to work out your fertile days, and it's cleared by the FDA to be used as birth control (FDA). That clearance is the whole point of the app, and it's why it costs $149.99 a year.
Her Good Days shows estimated fertile days only as a guide, labeled Not birth control. What it adds is the rest: menopause symptoms, sleep, food, pregnancy, workouts and a doctor report.
Feature by feature
Natural Cycles vs Her Good Days, side by side
| Natural Cycles | Her Good Days | |
|---|---|---|
| Price | $21.99 a month or $149.99 a year; core features need a subscription (App Store) | Free. No paid tier |
| Fertile days | From your temperature | Estimated fertile days, labeled "Not birth control"; never in teen mode |
| Birth control | Yes. FDA-cleared contraceptive software (FDA) | No. It's not birth control |
| Perimenopause and menopause | NC° Perimenopause tracks temperature and symptoms until post-menopause | Hot flashes per week and the hours they cluster in, sleep next to night sweats, cycle gaps over 60 days |
| Pregnancy | Pregnancy planning and pregnancy modes | Week and due date, appointments with your questions, kick counter, contraction timer, a baby card each week |
| Report for your doctor | Not stated in the listing | A PDF for the dates you pick: periods, cycle lengths, each symptom with how often and how strong, sleep, medications, your notes |
| Teens | Rated 16+ | From 13. Teen mode has no shop, no weight-loss goals and no fertile days |
| Use without an account | Go Anonymous separates your identity from your cycle data (NC° Secure) | Private mode: no account, and nothing leaves the phone |
| Ads and tracking | Label: email used to track you; Play: no data shared with third parties (Google Play) | No outside analytics code |
| Watch and wearables | NC° Band, Oura, WHOOP, Garmin, Apple Watch Series 8 or newer | Not yet. Steps come in from Apple Health or Health Connect |
| Platforms | iPhone, Apple Watch, Android | iPhone and Android |
How we source this. Natural Cycles cells come from the US App Store listing, NC° Secure, Google Play and the FDA De Novo record, checked October 30, 2026. Natural Cycles is a trademark of its owner; Her Good Days isn't affiliated with it.
Pricing
Natural Cycles pricing vs Her Good Days
US App Store prices on October 30, 2026.
Her Good Days
Free, every feature
| Every feature | $0 |
| Paid tier | None |
| Trial | Nothing to cancel |
Natural Cycles
Subscription
| Monthly | $21.99 |
| Annual | $149.99 |
| Free tier | Core features need a plan |
Privacy
How Natural Cycles handles your data
Go Anonymous separates your identity from your fertility data, so Natural Cycles itself can't link the two, and the company says it uses encryption and pseudonymization (NC° Secure).
Its App Store label lists your email as used to track you, and on Google Play it says no data is shared with third parties (App Store, Google Play).
Which one to pick
| Pick Her Good Days if | Natural Cycles fits if |
|---|---|
| You want hormone-free birth control from an app. |
How to switch from Natural Cycles
Step 2
Start Her Good Days
Pick your stage and enter your last period. Your fertile days show as estimates only.
Step 3
Cancel when you're ready
Cancel the subscription where you bought it, then delete the Natural Cycles account.
Other comparisons
Questions
Is Her Good Days birth control?
No. Its fertile days are estimates, labeled Not birth control. Natural Cycles is FDA-cleared as a contraceptive.
Is Natural Cycles free?
No. Core features need a plan: $21.99 a month or $149.99 a year on the US App Store.
Does Natural Cycles work in perimenopause?
It has NC° Perimenopause, which tracks temperature and symptoms until post-menopause. Her Good Days tracks perimenopause symptoms and sleep.