Only had a hormone surge for 1 day?

I've been taking digital ovulation tests every day of my fertile period. Friday morning I got the smiley face so we had sex twice Friday night, I took another test this morning (Saturday) the day I'm supposed to be ovulating according to the app and I just got the empty circle. I thought I was supposed to get two days of the smiley faces, the day before I ovulate and the day of, so I'm a bit confused.

Should I be taking them morning and night? Did I miss out on my best chance of getting pregnant by waiting until 12 hours later to have sex? Any advice would be greatly appreciated 🙂