A strong positive ovulation test that turns weak usually means that ovulation has occurred, but there may be instances where the results are inaccurate. Ovulation tests are used to predict the approximate time of ovulation by detecting luteinizing hormone levels in the body. Normally, before ovulation, luteinizing hormone levels will reach a peak, at this time the use of ovulation test paper will have a strong positive performance, after ovulation, luteinizing hormone levels will slowly decline, and at this time, the test, ovulation test paper may turn from a strong positive to weak. However, the results may be inaccurate and may be related to the quality of the test. Ovulation can also be determined by monitoring the growth of the follicles with ultrasound. Ovulation usually occurs about 24 hours after a strong positive ovulation test, and the probability of a successful pregnancy is higher at this time.