Today’s blog is about how the Natural Cycles’ algorithm works, aiming to answer questions like why upcoming fertility predictions can vary and why ovulation day can differ from one cycle to another. We also wanted to give our Cycler’s an exclusive sneak peek at the new app interface that will be released later this year. Please let us know your thoughts!
The Natural Cycles’ algorithm works by calculating your fertility based on the temperature readings and LH tests you enter into the app from the very first measurement up to the most recent.
Both the weekly and monthly forecast’s found on the calendar view are fertility predictions (indicated by question marks and hollow circles) that are completely tailored to each individual, mapping your unique cycle and important events, like ovulation, with the highest precision possible from the data you have already entered into the app.
However, like all predictions, your upcoming fertility can change as unfortunately we cannot see into the future! With every new data entry, the app’s algorithm adapts and adjusts accordingly to help paint the clearest picture of what you can expect in the days to come. This is why we always say check your fertility status each day – especially around ovulation – as it can differ from what was forecasted the week before!
Data entry and cycle variations
A key determining factor for forecast variations is data entry. The more data a Cycler enters the better the algorithm can be at determining your cycle’s usual pattern and thus predict what is coming up. So gentle words of encouragement – try and measure as much as possible to improve your data!
Cycle variations, such as a delayed ovulation day can be another reason for changes in your calendar. Cycler safety or their success is our priority so if the app detects something unusual it adapts by either a) giving more red days to be sure you’re protected from the risk of pregnancy (prevent) or b) advises you to keep trying as you’re likely to be highly fertile (plan), respectively.
Below is the in-app notification for Prevent users that will pop up if your ovulation is delayed.
Alternatively, for Plan users this in-app notification will be displayed if your ovulation day is delayed.
Cycle variations are common as the follicular phase (before ovulation) often varies in length. For instance, if you ovulated on day 18 on your previous cycle, it doesn’t mean that you will this cycle or even next.
A Cycler will only get green days once it is clear you have ovulated (with a clear rise in temperature) and is confirmed by the app. The app confirms this with a blue egg icon on a filled red circle on the calendar view or a blue egg icon and blue line seen on the chart/graph (see below).
Ovulation day has changed
A couple of observant Cyclers have noticed that when looking back at their previous cycle their ovulation day has changed by a day or so. This is because the algorithm is constantly trying to calculate the exact day of ovulation even after it has already happened! Once your luteal phase has ended, which is indicated by the start of your period, the app has more information to work from. With this extra bit of information, the app really does know when you ovulated and uses this to create an even more accurate picture of when you will ovulate this next cycle.
You can see that the app is continuously working very hard to get to know your cycles – variations and all! Natural Cycles adaptability to women’s cycles no matter what shape or size they are – long, short, irregular – is what makes it suitable for almost anyone. You can be assured you are always protected.
How will the new app differ?
The new app, that will be released later this year, will be even more intuitive and easier to follow. You can see below that it has been designed so that your fertility for the day is the core focus.
The upcoming fertility predictions will only be visible if you request to see them via the ‘Tap to show’ button. This way we can ensure that you feel confident about your actual fertility status instead of relying on predictions that may change.
Let us know what you think?
The Natural Cycles Team