Marcus Bell taught his son to ride a bike, to read, and to say "I love you" before bed. For nine years, he never once questioned whether the boy was his. It took one small, ordinary number on a hospital form to unravel everything.Elena had known from the start. When she found out she was pregnant, she had counted the weeks on her fingers three times, and three times the math had come out the same. The baby wasn't Marcus's.