How does Natural Cycles determine my conception date?
The conception date is the date of your last detected ovulation, as this is when conception occurred (when the sperm cell met the egg cell). Traditionally, conception dates are based on period data. However, since Natural Cycles detects when you ovulate based on your temperature and ovulation test data, it is able to use the ovulation date as the true conception date.
You can read more about how the algorithm detects ovulation here: How Natural Cycles detects ovulation
Can I edit my conception date?
It is not possible to manually adjust your ovulation/conception date as the algorithm will place ovulation based on the data that you’ve logged during your cycle.
That being said, if there isn’t enough temperature data around your ovulation day or your temperatures have fluctuated too much, you can instead edit your due date, and this will cause your conception date to adjust accordingly. This is because your due date will always be 38 weeks after your conception date in the app. Find out how to edit your due date in this article: How to edit pregnancy dates