Confused! 😩

Ok so I tested with my first positive opk on the 24th had sex on the 25th and tested on the 25 opk and got a darker line than in the 24th. My question is do I go off my first positive opk and assume I ovulated 24-48 hours after that or the higher darker positive on the 25th?! I feel like it makes a difference to whether or not I will conceive this month.