Theoretically 5-6 days after ovulation is beyond the window period, but there is a chance of pregnancy. The window period for ovulation is defined as the four days after the five days before ovulation, during which it is easier to conceive. Theoretically, the egg survives for 1-2 days in the fallopian tube after being released from the ovary. Sperm can maintain its ability to fertilize for 2-3 days in a woman’s reproductive tract, so it is easy to conceive in the days before and after the egg is discharged. The ovulation period is also known as the fertile period or the danger period. However, the calculation is not accurate if the menstrual cycle is irregular. Methods to determine ovulation include: date projection, basal body temperature measurement, observation of changes in cervical mucus, ovulation test, continuous monitoring of ovulation under ultrasound and measurement of sex hormones in the body. It is recommended that those who need to prepare for pregnancy should consult a professional fertility hospital.