With OPK's the test line will always be there.. so you will always have 2 lines no matter what time of the month you do it, ovulating or not. It is just when that test line is the same or darker than the control line is when you are close to ovulating. Once you see that darker test line, you are usually due to ovulate from 12-36 hours afterwards, so any time i guess you see that line the same as the control line, go for gold!

I used OPKS with DD was we were swaying for a girl and wanted to know when i ovulated for my cut off. They worked will for me.

Best of luck.