OPK lines..


I totally understand that the lines have to be of equal color to be a positive.

If I take the test one day and the second line is almost as dark as the control line the next day it may be very light then the next positive but the same evening barely there and then the next day close in color but not quite and so on... I’m very confused here

Is it suppose to get progressively darker as u near ovulation or does it not matter pattern wise!?