Rhythm method accuracy using NFP charts

[jlc2k2]

You would have NO such assurance. Any given month could have its own pattern, it’s own deviation from “averages”. Calendar rhythm is simply averages.

Those who are not actively charting their CURRENT fertility would be said to have abandoned the method in any of the scientific methods.

To further support this, I think I have an example of what the OP was looking for. A couple months ago I looked at my last 22 months of charts to see if the rhythm method rules ‘worked’ for me. I defined ‘worked’ as my confirmed fertile window (by STM rules) falling completely within the no-go dates for this particular rhythm method. I didn’t actually use the rhythm method - just looked at my historical charts. A conservative set of rhythm method rules (I can get the exact cycle day range later) worked for every cycle except the one I was in at the time.

So while it was a fun intellectual exercise, it proved to me that charting and following the rules of a real NFP method are worth it unless we are prepared to handle an unexpected pregnancy.

 

[yellow8yellowM]

Thank you for your help!

To further support this, I think I have an example of what the OP was looking for. A couple months ago I looked at my last 22 months of charts to see if the rhythm method rules ‘worked’ for me. I defined ‘worked’ as my confirmed fertile window (by STM rules) falling completely within the no-go dates for this particular rhythm method. I didn’t actually use the rhythm method - just looked at my historical charts. A conservative set of rhythm method rules (I can get the exact cycle day range later) worked for every cycle except the one I was in at the time.

So while it was a fun intellectual exercise, it proved to me that charting and following the rules of a real NFP method are worth it unless we are prepared to handle an unexpected pregnancy.

 

[jlc2k2]

To further support this, I think I have an example of what the OP was looking for. A couple months ago I looked at my last 22 months of charts to see if the rhythm method rules ‘worked’ for me. I defined ‘worked’ as my confirmed fertile window (by STM rules) falling completely within the no-go dates for this particular rhythm method. I didn’t actually use the rhythm method - just looked at my historical charts. A conservative set of rhythm method rules (I can get the exact cycle day range later) worked for every cycle except the one I was in at the time.

So while it was a fun intellectual exercise, it proved to me that charting and following the rules of a real NFP method are worth it unless we are prepared to handle an unexpected pregnancy.

Just getting back to this. The extra strict cycle days I was using for the rythm method were cd 7 - cd 22/23. A more traditional cd 9 - cd 20 would have had 7 cycles where I would have potentially been fertile outside the no-go days. 6 of those were cycles where STM shows me at 4 or 5 days before ovulation on cd 8.

This is out of 25 recorded cycles. So for me rhythm method is certainly not a good bet AND would likely result in more abstinence than necessary.