What is going on?!

I have no idea what's going on with my body. Here is a quick rundown... I went off birth control in October. While on birth control my cycle was always 28 days. My first cycle off was 36 days but then my 2nd cycle was back to 28. During that cycle I received a positive opk (clear blue digital) on CD17. This cycle I never got a positive (tested CD11-23) and glow predicted af would show yesterday (1/22). Af never showed and I for a bfn yesterday morning. I tested again this morning and got another bfn. Just randomly, out of curiosity, I took an opk as well... POSITIVE! What the hell? I'm on CD35 and getting a positive opk? I don't understand! Any help or advice would be greatly appreciated!