Bbt, help please!

Hey guys! So fertility friends says i ovualted cd 10, I got positive OPK on cd10 but i had an ovulation dip on cd13.. this is so confusing!  Would that be accurate? If this is right then I would be 14dpo, I have no signs of AF at all or any other symptoms. Trying really hard not to get my hopes up since i tested negative yesterday 😫 any advice would help. Thanks guys!