Could fertility friend charting be wrong?

Question

I just started charting with fertility friend and it says I ovulated on the 20th, but according to my cm and just the way I "felt" I'm sure I ovulated on the 22nd. I got a positive opk on the 20th and my temps didn't start to rise until the 23rd. I'm just curious if it's possible the chart is wrong

http://www.fertilityfriend.com/home/20c828

Answer 1

Fertility friend can definitely be wrong. It's really just a guesstimate of when they think you could ovulate... nothing is concrete. You're going to know your body better than the computer program and it's good that you check your cm because that is way more accurate. Good luck