For women who are preparing for pregnancy, ovulation test strips can predict the time of ovulation and improve the success rate of conception. The principle of ovulation test is to detect the luteinizing hormone (LH) level in a woman’s urine to predict the time of ovulation. For the accuracy of the test, it is recommended to determine and calculate the menstrual cycle and ovulation date before the test. The period from the first day of the month to the day before the next period is a menstrual cycle, usually 21-35 days, with an average of 28 days. The day of ovulation is usually 14-16 days before the next menstrual period. Starting a few days before ovulation, you need to test every day until a strong positive result appears, and after a positive test result, test every 4 hours, once it turns weakly positive, it means you have ovulated. If you have a need for fertility, you can have sex during the period from strong to weak positive to increase the conception rate. Ovulation test strips are used by holding the strip in your hand, dipping the end marked with an arrow into a container of urine up to the mark, leaving it for at least 3 seconds, then removing it and placing it flat and reading the result in 10-30 minutes. The appearance of two purple lines on the test strip, with the color of the test line equal to or darker than the reference line, indicates a positive or strong positive test, indicating ovulation within 24-48 hours. The test will be taken every 4 hours thereafter until a weak positive, i.e. the color of the test line becomes lighter than the reference line, which indicates ovulation. Urine from 10:00 am to 8:00 pm can be used for testing. The best time to collect urine is on the 11th day after the start of menstruation and monitor for 1 week. It is important to note that the urine should be tested in a clean, dry container. Do not drink water 2 hours before the test, as drinking water will dilute the concentration of luteinizing hormone in the urine and affect the test results. Do not touch the reaction film with your hands before use to avoid damping the test strip and affecting the test results.