Serious question lol

Leah • ✨Leah✨PCOS 👣🌈 Angel baby 12-13-17 👶 Arianna Kaitlin 8-24-09💜 Engaged 💍 Rainbow baby due 11-21-2020 🌈

How do you know if you for sure ovulated? I had positive opks the day before yesterday and also yesterday an now there negative. So how will I know if I truly ovulated or not?