Which Is Most Likely My Conception Date If My Last Menstrual Period Was November 26?

Hey, I’m currently pregnant at 19 weeks and due date September 1, 2021. I keep track of my cycle with the app Flo. According to the app I was ovulating on the 8th. But I’m not sure how accurate it is. I’m trying to determine what day did I conceive. My LMP was November 26th. I had sex on the 8th and 12th of December. What day did I conceive my baby.