I haven't been charting but my cycles are always 28 days and I put my last period date into FF and it said that my forecasted fertile days would be day 11-14, but I didn't get a positive OPK until day 16 and 17. So, my question is are OPK's usually right if they give a positive?
Re: Question about OPKs
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Yes, OPK's are accurate. Fertility friend takes them into account when determining your O date. Just remember that it is just telling you that you will ovulate not that you already have. I would suggest charting it's the only way to for sure know what's going on. Good luck!
FF just predicts, until you temp for 3 days after you O and have a temp change it just goes with a guess of what is perceived as normal O time. The OPK determine your surge with cause be a day or two before you O or 12hours before.
I am for normal 31 days but I do not O til day 23 not the "normal" day 17 it predicted my first month. The first month on FF is all guessing til you have the temps recorded.