Ovulating early

I have been getting cramps since yesterday which is rare during this part of my cycle. I've finished AF last Wednesday. I then noticed EWCM yesterday and today. This is way too early for this given I have a max of 35 day cycle. I took an opk just to be sure as I feel as I am due to ovulate. Low and behold a faint line which I don't normally get until day 15-18. Given all this I think it's fair to say I will be ovulating early this month. I'm currently on day 9 Just wanted to know why this would happen so early?