Clear Blue Ovulation Kit Question

I have decided to use Clear Blue Ovulation sticks this cycle. I have now had 9 days of flashing smiley faces and on day 20 of my 31 day cycle. I am worried that I have yet to get the solid smiley. I was assuming I ovulate around day 17. Should I continue to use the sticks or did I not ovulate this month? Any insight would be SUPER helpful and appreciative!