Ovulation test strips are used from day 11 of the menstrual cycle. For women with regular menstrual cycles, ovulation is relatively fixed, usually in the middle of two menstrual cycles, i.e. days 11-20 of the menstrual cycle, and the day of ovulation is around days 14-16 of the menstrual cycle. Starting from day 11 of the menstrual cycle, use an ovulation test strip to check for ovulation. When a red band appears in the test area of the ovulation test strip and gradually deepens in color, it indicates that the follicles of the ovaries are about to develop. When a strong positive ovulation test strip appears, ovulation will occur within 24-48 hours. Women who are preparing for pregnancy can schedule intercourse at this time, once every other day, to increase the chances of conception after intercourse. If after repeated ovulation test strips monitoring, you have intercourse during ovulation but are not pregnant, it is best to monitor ovulation at the same time with ultrasound.