Clear blue digital help!!!!

I am so confused and can really use some help! This is my third cycle using the clear blue digital opk. Im regularly on a 28 day cycle. The last 2 cycles i started testing on cd8 as instructed and went from low straight to peak on day 10 and missed my highs. I thought perhaps I had started testing too late. So this cycle I started on cd4 and again went from a low straight to a peak on cd5 which I thought was unusual. I waited the 48 hours for the peak face to go away and started testing again. On cd7 another peak, waited again and cd9 got a low then on cd10 got a peak and another peak on cd12. I'm so confused! What's going on???