When do you ovulate after positive OPK?

Al

Ladies I'm really confused. I've heard that you should count ovulation 24-36 hrs after first positive, and I've also heard after peak. Glow seems to do the next day after first positive, but Premom does the day after peak. Premom also says that if you have a prolonged positive (multiple days) you ovulate only when that goes negative. I've looked up a couple of scientific papers and twice now I've seen that they say ovulation is 35-36 hrs after peak. There are too many conflicting pieces of information 🤪 Does anyone have any experience or resources they could share with me to help? I'm thinking I should believe the scientific papers otherwise...