AF due August 17th....questions

I'm having a hard time with figuring out when I'm ovulating. All the symptoms that can happen i.e. Sore breasts, milky CM, increase in body temp, etc., happen AFTER I'm supposed to be ovulating. I just finished ovulation a couple of days ago but my breasts became sore today and I had an increase in CM. I've taken ovulation tests in the past but got negatives on all of them during the time I was supposed to be ovulating. I've been to the doctor and she has reassured me all is fine and that I am ovulating. Then why do all my symptoms happen after the time I'm SUPPOSED to be ovulating?