[Amazing Yorkies]

I had twin boys once. Mom was busy working on a baby, and I noticed the sack seemed lumpy.. I checked things out a little closer and there was another baby. If I hadn't been there, I don't think it wouldn't have made it because Mom was working on just the one, and the sack was still covering the face of the other. Their cords attached to the same one big cord that went to the afterbirth, which was really weird too. As for twin bonding, I never noticed anything different from any other litter mate.
Congratulations on your new baby!