A strong positive ovulation test result only indicates that the luteinizing hormone level in the body has reached its peak, indicating that the mature follicles will be expelled within the next 24-48 hours, not that the mature follicles have already been expelled from the ovaries, so intercourse at this time is a bit early and the probability of conception is slightly lower than after a strong positive result turns negative. When the result changes from strong positive to weak positive, it indicates that the follicle is expelling or has already expelled, and the chance of conception is higher. If conditions do not allow, you can arrange more intercourse after a strong positive result to achieve the same effect. The survival time of eggs is shorter than that of sperm. A mature egg can survive for 18-30 hours after it is discharged from the ovary and enters the fallopian tube, so in general, a woman is more likely to conceive if she has intercourse within 72 hours before and after ovulation, which is about 3-4 days after the start of a strong positive period. If you have been trying to conceive for more than a year and still have not conceived successfully, this is when you need to go to the hospital to seek the cause. Men need to have their sperm count, vitality and morphology tested, while women need to have their ovaries’ function, the patency of their fallopian tubes and the environment in the uterine cavity checked. If the infertility is due to a disease, treatment or IVF can be used to conceive under the guidance of a doctor.