Differing fertile window dates online

[Lottie Tobe]

More of a rant than a question....why is it that different ovulation calculators/apps suggest differing o dates and fertile Windows?!

Fertility friend app window was this week (fairly sure was correct from cm and positive opk) but other apps looked at suggest I still have three or four days to go.

So annoying, now doubting myself - sick of dtd! Anyone else find this?

 

[BlondeP]

Yes!! I have two apps recommended to me by friends and both are different! Not massively but enough that my most fertile days are a good few apart according to them!

 

[Slb24]

Are you able to change the cycle lengths on them? I've found that some don't give you the option and use the 'average' cycle length of 28 days. If your shorter or longer they don't work.

I would just use the ones you can change the cycle length xx

 

[Lottie Tobe]

These are ones you can have your cycle length. I just don't understand why they differ!

 

[Slb24]

I have no idea then! Haha sorry! Xx

 

[russellmuscle]

Because each woman it can vary when they ov so they have diff windows.

In my case mine were late. I OVd last cycle on the first day of my app fertile window.

Id either OPK or do smep. i didnt opk this cycle, did smep and hey presto.

xxxx

 

[Lottie Tobe]

Thanks Russellm. Makes more sense now! Feel confident I got the right end of the window then