Irregular cycles will cause your predictions to spread. In other words, you will see multiple days marked as the possible start of your periods and longer periods of predicted fertile days. This is not a malfunction; it is simply the consequence of the irregularity in your cycle characteristics.
You need to rule out any technical issue with your data entry first. For that just look at your cycle list (tap More/Charts Management on the App) and identify the cycles that are outside of your usual pattern or cycles with incorrect data. You may choose to exclude them from your stats. Make sure to uncheck the stats box for cycles involving pregnancy or miscarriage or cycles that were influenced by external causes.
Some conditions such as Poly-Cystic Ovarian Syndrome (PCOS) or perimenopausal symptoms may also cause irregular cycles.
Let your health care provider know:
If your cycles are irregular and you are not aware of any specific cause, you should mention it to your health care provider at your next appointment. It may not be a cause of concern however it may help your healthcare provider to identify potential issues.
Rely on your actual fertility signs:
If your cycles are irregular, you will need to observe your fertility signs more closely to figure out your actual fertility phase. Predictions will not be as useful in this case. Check our videos and online charting course if you are not familiar with these observations.