Positive opk but no ovulation detected. what does this mean?

Not always accurate: Odks are a convenient way to help time ovulation and the timing of intercourse, they are not always accurate. They can occasionally be positive but other more accurate signs of ovulation, like ultrasound, Progesterone levels and endometrial biopsy indicate that you did not ovulate. Mostly, however, when positive, odks indicate ovulation. May want to try a different odk or other tests for ovulation.