Accuracy of this app for ovulation days

Chels
So I was curious as to how accurate the ovulation days have been for others... I had sex on one of my highest fertility days... And he didn't pull out... (Smh, I know) well I didn't really think nothin of it until i randomly just gotten a dizzy feeling and nauseous feeling for a brief few moments... Maybe 3-5 minutes... It's been a week and a half since the date (Aug 30) and I'm not expecting my period until next week... Curious if I could possibly be pregnant or if the fertility prediction is wrong on this app...