OPK? Positive to fade out??

I usually have 2-3 days of positive OPK's, but this time I had 2 dark lines Sunday night with one a shade lighter (I took that as not quite positive), the following morning at 6 am definitely 2 dark lines. And we DTD at noon! I still had two double dark lines in the evening, but one was a shade lighter. Today my strip definitely has a very light line with one darker, so definitely negative.

It has never changed this fast for me, has this happened to anyone else? Kind of glad I had my attempts at noon and 11 pm last night :)

It doesn't matter how quickly your tests go negative as long as you got at least one positive. Your body ovulates when the concentration of LH in your system reaches a certain level regardless of how long it lasts.