Positive opk but no ovulation detected?

Not accurate: Odk are a good way to predict ovulation. Once the kit is positive, ovulation or the release of the egg occurs 26-40 hours later. Although generally accurate, the odk can sometimes have a false negative- you ovulated but the kit does not show it. Sometimes using another kit works or there is always the possibility that you are not ovulating. 3% of women have regular cycles but do not ovulate.