Is there a high chance of pregnancy having sex day of ovulation ?

Unprotected, yes: Obviously, unprotected sex can lead to pregnancy.

Yes that is how one: conceives. Actual conception depends on many different factors, such as friendly environment in utero, sperm count, presence of contraception or barriers, etc. but given all constants, ovulation day and 2 days before/2 days after gives you the best chance. Thanks for trusting in HealthTap.