Ovulation test strips are used to monitor the time of ovulation by detecting changes in luteinizing hormone (LH). Everyone’s menstrual period is different. For women with regular menstrual cycles (28-30 days), it is generally recommended to start the test on the 10th day of menstruation and test once a day. When the ovulation test paper starts to be positive and gradually strengthens to a strong positive, it suggests that the peak level of luteinizing hormone occurs, and the frequency of testing needs to be increased at this time. If the comparison reveals that the ovulation test paper begins to weaken and turns weak quickly, it means that ovulation is imminent. It is important to keep a dynamic record of the changes in the ovulation test results to make it easier to capture the critical time point of rapid weakening, and to indicate impending ovulation within 24 to 48 hours of the rapid weakening of the ovulation test. It is not recommended to use morning urine for testing. It is better to try to use urine at the same time every day, the best time being between 10 a.m. and 8 p.m., and compare the results over the course of several consecutive days of testing.