How long does it last?

So I'm on my first round of progesterone and Clomid and yesterday morning I got my first positive opk..

well because I was so excited I kept testing all day and they were all super positive☺ so this morning I wake up assuming that they will be negative now but it's still definite positive 🤔 how long does the surge last? We had sex Last night and used preseed thinking it was our only chance.