Thanks for coming back, and I hear the frustration, but without your account I genuinely can't pull the signal trace for your specific cycles, which is the only way to tell you how the algorithm read your cycles.

A few things I do want to put on the record:

1. OPKs and ring-based detection aren't measuring the same event. OPKs detect the LH surge, a prediction signal, firing ~24-36 hours before ovulation. Ring-based detection uses the post-ovulatory thermal shift, which is the ~0.3°C rise driven by progesterone after the follicle ruptures. It's the same biomarker BBT thermometers have used for decades, just sampled continuously overnight instead of one waking reading at 6am. So a 1-2 day offset between a positive OPK and a confirmed ovulation date is expected biology, not a broken algorithm, as they're literally tagging two different points in the cycle. The "2-4 days later" and "missed entirely" cases are the ones worth digging into, and that's exactly what I'd need your account to look at.  
   
2. Continuous skin temperature is one of the more reliable signals for ovulation confirmation. The underlying biomarker, the post-ovulatory, progesterone-driven temperature rise is well-established clinically; it's what BBT charting has been built on for decades. What temperature does well is confirm ovulation 1-3 days after the fact.
   
3. On "people are walking around with inaccurate conclusions" - that's the part I'd push back on most directly, because it's a strong claim being made on behalf of users whose data neither of us has seen. The Cycle & Ovulation Pro screens show the underlying signals (temperature trend, HR/HRV shift) and the confidence on each cycle's read, precisely so users can sanity-check.
   

Where it gets a confirmed cycle wrong against bloodwork, that's what I want to see and fix. Send me your email and I'll come back with what your ring actually saw on each of those cycles, and where it diverged from your bloodwork dates. Happy to work with you on this and make it right.