How do you know dpo?

Sydney

How have you guys been calculating dpo? Do you go by when your temp was the highest? Or when you have cramping, or by what an app says? My app said I was going to ovulate on the 16th, but I had some serious cramping on the 15th (didn't temp) and had ewcm the 13-16th. Do you think it's safe to assume i ovulated on the 15th? Or isn't cramping a good way to tell?