The chances of getting pregnant are 30-50% if you have intercourse once during ovulation. It is not always possible to get pregnant during ovulation, as there are many reasons for not getting pregnant. There are female factors, including fallopian tubes, reduced endometrial tolerance, chronic inflammation, and pelvic adhesions that can cause infertility. Male factors also play a large role, if the sperm viability is relatively low, can also cause non-pregnancy, so it is not always possible to get pregnant by having intercourse at the time of ovulation. The chances of getting pregnant are significantly higher when you have intercourse during the ovulation period. You can get pregnant if you have intercourse within 10 days, 5 days before and 4 days after the ovulation period, plus the day of the ovulation period.