So, these tests tell us that ovulation is close, but what about when it has happened? Does the test fade back to negative quickly once ovulation is over? Should it come up positive for a certain amount of time?

For example, say my AM test is close to positive, then the same day my PM test is a clear positive. Should I expect it to stay positive for any amount of time or is it normal if the next days AM test is clearly back down to negative?

Just trying to understand these and pinpoint my window.