Vanishing twin... Any hope they are wrong?

Tricia
We found out today at 8.4, that baby "b" is not viable, and they said it's a vanishing twin.
I realize I'm totally grasping at straws... But any chance at 12 weeks we might see baby? 
I realize there is obviously no well to know for me, just wondering if it's happened to anyone.
I feel such a loss, but am just praying for a miracle.
At 6 weeks we saw two sacks the same size, but could only see one yolk sack, then today looks like it's vanishing. :/