Which OPK should I consider my +?

Rashida

I have been taking OPKs this month and for the first time ever I got a positive where the lines were the same color on CD20. On CD21, the tests were dark lines but not positive. Didn’t test CD22. Well today I just tested again and now the test line is much darker than the control line. Should I now consider this my true LH surge or did I surge CD20?