I agree with hj, looks like if you o'ed it would be cd 16. It's possible FF will still you CH, just keep temping. in the meantime, I would always trust your chart as long as you're consistant and following the temping rules.
mine is the same way - keep in mind that CBEFM measures LH and I think estrogen level - which only says you are about to O not that you did. So if you had a peak and Od a day later then that may be ok. Mine often disagree so I just BD on all the days that they charts and monitors say to.
Re: WDYD when FF and CBEFM disagree
Your other charts have Ch around CD14, and 13...which looks about right to me.
If your are doing CBEFM as well I would just have sex on those days too! I doubt it will be that different from FF, based on your other charts.
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