How to tell how many DPO?

[Cienega]

Hi all, I got peak opk 2 days ago on Thurs am 13th May. It was back down to high by that night and all day Friday then down to low from today. I don't think I ovulate too long after peak opk so am I right to estimate that my ovulation day was Friday 14th, one day after peak? Thanks all!

No one will be able to give you a very accurate answer to this - ovulation happens generally 24-36 hours from your LH surge x

It could have been the same day, day after or day after that - none of us will know unfortunately! People that don't track bbt tend to count O as the day after the peak unless they specifically felt twinges or had EWCM to guide them otherwise.