Please help very confused

I have longer cycles 35-40 days and sometimes they are irregular. We are ttc #2. On CD 19 I got a high opk but not peak. We BD almost every day of what would have been that fertile window if I ovulated. I assumed I missed the surge somehow because when I tested on CD 20 it was low again. I continued to monitor cervix and opk in the following days and nothing seemed out of the ordinary. On CD 34 (when I was expecting AF to arrive) I received a peak on opk and had a high open cervix. So I thought I must had just ovulated late this cycle and was hopeful. Now today, CD 36 AF showed. What the heck is going on? What does this mean?