I have had as many as 5 +OPK's in a row using the brand Confirm and testing in the morning (2nd morning pee). I now test in the evening and only get about 3 positive days with that brand. So the time that you do the test does make a difference. I am now using a different brand (Fortel) and I test in the evening (about 6.30) and only get about one day of positive.

By the way, I have fallen pregnant using both brands in the past.
Debbie