Ovulation test paper strong positive lasts for 1-2 days will turn weak, ovulation test paper is through the detection of urine luteinizing hormone peak to determine whether ovulation. About 1-2 days before ovulation, the concentration of luteinizing hormone in the blood rises rapidly, and the luteinizing hormone in the urine will also rise, so the test will appear strong positive, because the luteinizing hormone is not released into the blood in a balanced manner, usually in the morning the concentration will be relatively high, so it is recommended to use ovulation test paper to test at about 10:00 am or 8:00 pm, and it is best to fix the same time to monitor. Ovulation will occur in a day or so after a strong positive ovulation test, and the egg can survive for about two days after discharge, so you can reasonably arrange your sex life according to your fertility plan or take safe and effective contraceptive measures to avoid unwanted pregnancies.