Ovulation and apps

When I enter a positive ovulation test on Glow and my other apps, it always puts ovulation as the next day. I know it's an estimate but everyone says that after the positive test then should ovulate between 12-36 hours after. I'm kind of worried cuz I had sex the day before and the day I got a positive test. We weren't able to have sex these past few days because it's been busy. I'm worried our chances are decreased if, for example, I ovulated 36 hours after the positive. It says I ovulated on the 18th and now my FW is over.