Found mallard duck eggs, trying to save them! are they alive or dead?

Okay so, Sunday I was outside and I saw a duck and when she saw me she ran away. I noticed that there was a nest with 14 eggs in it. I didn't touch them. I kept waiting for the mother to come back but she never did. So yesterday (thursday) I went and took the eggs to try to save them. Whenever I picked them all up they were verrry cold. So I took all the eggs and made a nest like thing out of my heated blanket. Now they are all warmed up and fine. But I don't know if they are alive or not. This whole thing is random I've never done anything with hatching eggs before. I candled them and the only thing I see is like an orangish oval in the middle. At the bottom of the egg there's a small circle. I think its the air sack maybe? I don't know I've been getting all my info from google. But I checked them this morning and there still isn't any of the red veins that there should be. I don't know what to do:(