I always felt like someone was missing. When I first heard about vanishing twins, I knew that was the answer. I decided when I was around 11 I was having twin girls. Even finding out I was adopted didn't answer that feeling of someone missing. My mother swears I was a full-term singleton (& my original birth registration agrees), but I weighed under 4lbs. I had no issues except being small, which just makes me more suspicious I had a twin for at least a few months.