Ovulation test strips test a woman’s luteinizing hormone. A strong positive test indicates that the luteinizing hormone has reached its peak, signaling that ovulation may occur within 24-48 hours. Two consecutive positive days indicate that ovulation is imminent, and a subsequent change from strong to weak indicates that ovulation has occurred. If you are planning to get pregnant, you can increase the frequency of intercourse when there is a strong positive test. Because the sperm can survive for about 72 hours and the egg can survive for 24 hours, increasing the frequency of intercourse at this time can increase the fertilization rate. This is especially important for women with irregular periods.