Happy Mommy- it is not uncommon for one twin to pass away in the womb in
early pregnancy and is often termed Vanishing Twin Syndrome. When that happens you can bleed but the baby's body is absorbed back into your body at this young age. If you were further along, close to term, you'd more than likely deliver early to prevent anything from happening to the other twin as your body cannot absorb the deceased baby.
It's no comfort to hear any of this, I know. I'm so very sorry!