Ovulation test strips can be used to detect whether ovulation has occurred, and before and after ovulation ovulation test strips will appear different changes, due to the hormone levels in the female body will change, so in the detection of ovulation test strips will also appear corresponding changes. Before ovulation, the test paper will be weakly positive for about 3-5 days, after which the test paper will become strongly positive, indicating that ovulation has begun, and after ovulation, the test paper will begin to show weak positivity, and the weak positivity of the ovulation test paper will continue for a period of time until it disappears completely. However, it should be noted that monitoring ovulation through the ovulation test paper is not completely accurate, it may be affected by various other aspects, if you want to monitor whether ovulation, you can go to the hospital for ultrasound and other related tests, the relative test results are more accurate.