A blighted ovum is a common cause of miscarriage early in pregnancy. Learn more about signs and symptoms, why it happens and more. Because it occurs within just a few weeks of ovulation and fertilization, many women aren't even aware that they were pregnant in the first place. My Misdiagnosed Blighted Ovum Story. I've been sharing my story for several years online. Yesterday I went to my first ultrasound at 8 weeks. The tech found a gestational sac and "possibly" a yolk sac but no baby. I lost all hope that this could still end with a take home baby but now, after.