Opks and ovulation

Ok so I purchased a big batch of ClinicGuard Opks about 7 wks ago and started using when AF ended on 1/9 & I've been monitoring my CM as well. Well, I did notice my CM went from sticky, then creamy, then creamy/slippery(the day AFTER Glow predicted my peak day). 
Now, with the opks, I'll list them below. But to be honest, the predicted peak day, which was 1/19, I got a slightly dark test line, then yesterday 1/20 I got darker test lines, but not entirely as dark as the control line. Anyways, 1/20 I had a pain in my left pelvic area that ran around my back the entire day. It was literally like I could feel an egg leaving my ovary. (As crazy as that sounds.) 
But later that evening I got another dark opk, but like I said, not exactly as dark as the control line. And then today i test again and then test line now looks like it's fading. Has anyone had a bad experience with these, or got pregnant even when the control line wasn't EXACTLY as dark as the control line... Tell me what yall think plz