Majorly confused...

Emma

I came off the pill 8 months ago for ttc, my cycle was initially 40 days then after 3 months went to somewhere between 28-31 days. This month I didn't manage to find a peak on opks even with doing them twice a day, I tried bbt for the first time this month but my chart seems to spike up and down. I am now on day 33 of my cycle with no sign of Af.....any clue as to what is going on with me?