FertilityFriend predictions

[Sorsha]

FertilityFriend is confusing me this cycle... It says that my average O day is CD 16 and on the graph it has CD 16 (August 30) as the predicted green day, but on my calendar it's showing CD 17 (August 31) as the light green O day. Any idea why the calendar would be showing things differently?

See attached screenshot...

 

[Dill]

Not sure. I'd contact their support staff about it. They're great about getting back to you quickly!