LOL LIsa! JUst a little aside. I have been an avid opk user for 2 years now (gotta love Lullaby! ) and whilst it's true that you will ovulate usually within 24 hours it can be up to 48. With this pregnancy I was on 150mgs of Clomid. I was having regular follie u/s and despite 3 follies being HUGE I hadn't ovulated. So I was given a trigger. I ovulated 48 hours post trigger (just under).

If you don't know what that is Sassy it's a dose of hcg which mimics lutenising hormone which is what makes that follie release it's egg! It's the LH that the opk is measuring. So, effectively I surged on a Friday but didn't release my cargo for 2 days!

So, the moral. Get jiggy with it as soon as you get a positive (or close to it) and dtd for the next 3-4 days.