Unfortunately my little one died before I could get him out of the shell

I think his mate is also dead, although I haven't opened the shell to assess it.
I seem to have the worst luck ever with hatching, doesn't matter broody or incubator none of them seem to work for me.
I do have a candling question, I am incubating guinea eggs in my hova bator, tonight marks the end of day 21, (7days to go) I quickly candled them and I don't see movement in any of them

the shells are very thick so they are hard to see through. I Can see a distinctive air cell, but the rest of the egg looks very black with no movement. Is this normal I was sure that I would see movement right up till hatching? does this mean that they are all dead? I want to prepare myself in case next week nothing hatches. please let me know your thoughts.
This is such a stressful addiction