Ngocsura80, The shettles method states that doing opk's twice a day would give more accurate readings, I use to find that I was getting positives two days in a row also and so I read Shettles when I got interested in swaying and yeah I changed my opk time to 8 - 9 pm because I O in the early mornings/ late evenings but took a couple of double tests per day for months to work that out.
Hopefully you catch your egg, and get your blue bfp 