What are the odds?

I was intimate with my husband on the 27th & didn’t even know if I was ovulating or not. I checked this app & it definitely said I ovulated on the 27th. I am not tracking & we are currently not trying right now due to me having a miscarriage back in July, but the spare of moments be there!😂😂. My question is, could you only have sex on ovulation day & still be successful at conceiving with only 1 day of being intimate?

Again, not trying right now maybe we will try again in December/January but whatever happens, happens right?