Positive OPK but no ovulation??

Is it possible to have a positive opk and not ovulate? I had a positive opk 2-3 days before I thought I ovulated, which btw was 5 days earlier than usual. I had a dull achy feeling in my lower abdomen and lower back most of the afternoon and I thought there was a small dip on my bbt bc it started to rise but then stopped and stayed the same temp for 3 days and then went back down a little. It is now CD 15 and there is no clear rise that has happened yet. I'm just confused. So can you have a positive opk and not actually ovulate??