How do you ladies know EXACTLY when you ovulated??

Natalie • Pregnant with baby # 2!

When everyone says “I’m 9 DPO” like I know you kind of have a estimation when you catch your LH surge, you will normally ovulate within the next 24 hrs.....but I never know EXACTLY when I ovulated?? Is Tempting or cervical mucous check the best indicator??? Any thoughts would be helpful.