Cycle Day 24 and still not ovulation

For the past 2 years of trying I have always ovulated on day 19 of my cycle. This month I took 150mg of Clomid just like I always do. But so far, no ovulation. I have emailed my Dr. to see what I need to do next. I am guessing to wait about another week and then start provera to start my period and start the whole process over again.
Has anyone had this happen to them?
 
Kelly