I took evening primrose oil for the first time ever this month. I took 1000 mg from af until ovulation. I am pretty sure that it made me not ovulate at all. I have a perfect 28 day cycle usually, and I was taking it to help with my cm. My opks never became positive this month for the first time ever (I kept telling myself that I must have missed the surge, but I knew it was weird). I spotted brown about five days ago and that was it. (I told myself that could have been implantation bleeding, but I'm pretty sure it wasn't.) Now I am one day late with no period symptoms and a negative HPT. I will never take EPO again! Not only did it not help with my cm, if anything it made it worse, and I am pretty sure it completely suppressed ovulation! I am ready to scream!