Opk help ovulation pains

I have reg 28-29 cycle. Was thinking I ovulated on day 15 like glow said but looks like I got my first positive on CD 11. I have also been having pains in my right side since that night of first positive. Never had ovulation pain before. So if I got a positive on cd 11 when did I ovulate? That day or the next? Because the pain started a couple hours after positive opk. The line was the darkest Ive gotten so far. It was even darker than the control line.