Which one is right?

Ke

FF says I ovulated on cd 12. Glow says I ovulated on CD 13. I got positive OPKs on CD 12, and CD 13, with a sharp drop to negative in the evening of CD 13, leading me to believe I ovulated on CD 13. If I did indeed ovulate on the 13th, I don’t think I had sex at the optimal times....???