The blank slate here refers to a negative urine pregnancy test. Thirteen days after ovulation with a negative urine pregnancy test there is still hope for pregnancy, which can be reviewed under the guidance of the physician. Fertilization after ovulation mostly occurs within 24 hours of ovulation, 6~7 days after fertilization, the fertilized egg is deposited and secretes HCG, it is necessary to determine whether you are pregnant or not through blood HCG about 10 days after intercourse, 13 days after ovulation, the concentration of urinary HCG is low, and the test results show a negative result, there is still a hope of getting pregnant, and then you can go to the hospital for a recheck. Patients should pay more attention to rest, maintain sufficient sleep, and reasonably supplement folic acid. Usually pay attention to appropriate exercise, eat more vegetables, fruits, reasonable supplementation of vitamin C, can enhance the resistance. When the result of early pregnancy test paper is negative 13 days after ovulation, it is recommended that the patient go to the hospital in time and have regular rechecks under the guidance of the doctor.