So I had my darkest opk 3 days ago and it still wasn't that dark but just assumed I ov then as I'm now on cd 20 but I'm getting sharp twinges on my left side today. It's been all day. I've had mild cramps since a few days ago. Could this be ov now? Very confused as it's cd 20? Cycles can be from 28 days to 34 days. X