Double Yoke Eggs - Twin Chicks??

One of my eggs currently in the incubator is a double yoke egg.  I've only had a couple of them this year.  Funny how last summer I had tons of them.


I did try to hatch a couple of them last summer but after candling them and seeing no signs of life I gave up on them.


I've candled the egg a couple of times and have had an air sac.  However the egg is a brown egg so it is hard for me to see veins like I see in the white eggs.  

The difference between the double yolk egg and regular eggs is huge (no pun intended).  I candled it again tonight and I think whatever started growing has died.  I'll give it a few more days as long as I don't get any funky odors in my incubator.  


So I did some googling and found that it is very rare to even get double yoke eggs.  They usually occur every 1 out of 1000 eggs.  It is even rarer to hatch twin chicks out of a double yoke egg.  I think human intervention was necessary to facilitate a successful hatch of twins.  


Well we'll see what happens but I'm not very optimistic.   Still I'll be thankful to have the other eggs hatch and have healthy chicks.