If ovulation is not detected during ovulation, it may be due to irregular menstruation, inaccurate projection of ovulation, low luteinizing hormone in the body, no luteal peak before ovulation, which will also affect ovulation during ovulation, and ovulation will not be detected, if the use of ovulation test paper is not appropriate, or ovulation test paper failure, ovulation will also not be detected. In general, ovulation is about 14 days before the next menstrual period, which is for women with regular menstruation and a menstrual cycle of about 28-30 days. If the menstruation is irregular, or the menstrual cycle is too long or too short, the projected ovulation period will be inaccurate and ovulation may not be detected. To determine whether there is ovulation disorder or other endocrine disorders that affect the normal development of follicles.