I have started using opks this month...I know they have to be just as dark or darker then the control line, I finished my period on the 31st and started using them..they have all been really light except for 1 which was I would say close to the colour of the control line.

I don't expect it to be positive until around the time of my fertile window 7th-13th so why was that one so dark so early?

Should I be testing twice a day?

Is there a best time to test?

Thanks for any help or info ladies ☺