Why am I not ovulating?

So, with the advice of my OBGYN, my last cycle I have been taking opk's and my period is now due tomorrow. According to my opk's, I ovulated 3 days ago. But it's so close to my period, I'm not really sure if I did or why I would be ovulating so late. I've been taking metformin to hopefully help with my issues with ovulating. Does anyone have any advice, or is anyone else dealt with this and still gotten pregnant?

I was told to test throughout one full cycle, because I hadn't been getting any positives when I "should" be ovulating. And these are the results that I got.