Confused can someone help 🤦‍♀️

Lois

I got a positive opk on the 15th I tested again the following day 16th and it was back negative so I'm just wondering did I ovulate on the day I got my pos opk ? Or would I of ovulated 12-36 hours from the positive I'm supposed to be 13dpo today sorry if i come across dumb 🤦‍♀️ it's my first month tracking my ovulation