Duck Egg Development

This is a Pekin duck egg. I started the incubation process on 10/11/15. This video was taken on 10/25. I get so excited every single day that it survives and continues to grow. I have lost 4 of the original 6 eggs that I incubated on the 11th. I have 2 that are still surviving. This egg started out as a double yolk. When it first started developing you could see 2 embryos but as time has passed only one is still visible. I am not sure if the other is hiding behind this one or if it didn't even make it this far. I figured if it was dead in there that the 2nd duckling would die too because of having the dead one in there. I am still a newby to this so if any of these ducklings survive I will just be elated! I have 10 thriving eggs at the moment. I guess we will see what happens!