Ummmm, what?

Just updated and it says that the average length of my period is -1415 days. What? Does my menstrual cycle go back in time? Is that a thing? I was annoyed at first but now Im rather intrigued. Maybe I should go see my doc. Hang on, Im going to look it up on WebMD.

Aubs99789 about Period Diary Ovulation Tracker, v2.7