Where do you start?

I had ovulation spotting on the night of the 14th. Just a little bit of brown and pink with cervical mucus when I wiped. But I had ovulation cramps and tugging and pulling on the night of the 15th and 16th. So did i ovulate the 15th probably? I'd never experienced ovulation spotting or cramping before. And no I didn't take opk, I had ran out but I was about 100% sure that's what was happening.