breathe ilo indicates the fertile phase, not ovulation itself.
It would be unreliable to set ovulation to one specific day, because it can vary from woman to woman and cycle to cycle and overlap two days. In order for your fertile phase to be correctly indicated by the breathe ilo cycle tracker, it is necessary to take the measurement at rest, sitting down and once per day.
Only then an accurate result can be guaranteed.
To learn more about the learning cycle, please take a look at our article “Why does braethe ilo need a learning cycle?”