Irregular period and ovulating

Ha
Is there anyone out there with an irregular period that still consistently gets a positive opk and bbt spike every month? Does your period always come 12-16 days after ovulating? I never get positive opk and have this crazy cycle that's all over the place. I deff do not have pcos and OB says I ovulate. I just can't seem to track it or catch it ever. Any thoughts or experiences?