Dear Ask The Doctor: If a breakthrough ovulation would occur while on the birth control pill, could it occur at anytime of the month, or only around the typical ovulation time (day 14)? I was late taking about 5 pills this month at various times in my first, second and third weeks (up to a maximum of 14 hours late for each pill I took late), and then on day 20 of my pill pack, I felt a distinct cramping feeling on my left ovary that stayed with me throughout the afternoon and evening, but was gone the next day. I also noticed egg white cervical mucus that day, as well as two days afterwards. I am on Yaz, and am now on day 25 of my pack (the first of the 4 placebo pills in this brand). Is it possible that I could have had breakthrough ovulation on day 20? And if so, theoretically, it would mean that if conception occurred I may not get my period in the next 4 days before starting a new pack, and that implantation would only occur around 7-10 days after day 20 (presumed breakthrough ovulation), which would mean that i should not take a pregnancy test until approximately 2 weeks after day 20, correct?