When an ovulation test comes back strongly positive, ovulation occurs in about 24 hours. The ovulation test works by detecting the peak of luteinizing hormone in the urine to determine the time of ovulation. When a positive test is detected, ovulation is likely to occur in about 24-48 hours; when a strong positive test is detected, ovulation is likely to occur in about 24 hours. Ovulation test can only estimate the approximate time of ovulation, whether ovulation will actually occur or not needs to be detected by ultrasound. If you have a strong positive test and a luteinizing hormone spike, but ovulation does not occur on ultrasound monitoring, you should consider the unruptured follicle luteinization syndrome and use medication to help ovulation under medical supervision. In conclusion, if you are planning to conceive, you can arrange intercourse when the ovulation test is positive, or you can go to the hospital for ultrasound monitoring of ovulation and combine it with the ovulation test to guide intercourse to improve the chance of conception.