How effective is emergency contraception the day of ovulation? if i have sex during ovulation, but take ec right after, what is my risk of pregnancy?

See below : Taking emergency contraception within 48 hours of unprotected intercourse decreases the chances of pregnancy by 75%.

EC: is up to 89 % effective when taken within 72 hours (3 days) after unprotected sex. It can reduce chance of pregnancy by up to 95% if used within 24 hours. It continues to reduce the risk of pregnancy up to 120 hours (5 days) after unprotected sex, but is less effective as time passes.