I had a + opk yesterday & today,when it's the best time to have sex? we've had sex the day before the +. how soon does ovulation occur?

12-48 hours: When the OPK is positive, the best time to "try" for a pregnancy is the night that it turns positive and the next night. Ovulation will happen in the next 12-48 hours. The egg will be available for 4 hours or so after ovulation; sperm can hang around for several days. So its important that the sperm are there waiting for the egg when you ovulate. Best wishes!