Opks don't work with 40-day cycles (here's what did)

spent months testing on day 12, day 13, day 14 like the box suggested. my cycles ranged 32-40 days though, sometimes skipped entirely. so yeah. the window was all wrong.

what actually worked: lab testing instead of strips. got my lh tested on what i thought might be ovulation day, got a number. a week later, got it tested again. the surge showed up in the results, not on a pee stick.

the metabolic piece matters too. i tracked my glucose with a cgm and noticed it always dipped around the same time my lh labs spiked. so the surge wasn’t random - it was tied to my metabolic cycle. cycle length + lh labs + watching glucose patterns = i finally knew when ovulation actually happened.

took my endocrinologist saying “your cycles are long, stop testing on day 12” for this to click. nobody mentions that opks assume a pretty standard 28-day timeline. what worked for other people with irregular cycles - did you do labs, or find a different tracking method?

anyway.

that’s exactly it, “opks assume a pretty standard 28-day timeline.” i’m dealing with cycles that went from 19 days to 42 days, so trying to guess a fertile window feels

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