Need help with candeling

[Demidog]

I'm new to this so please bear with me

I've been incubating my first ever batch of eggs since Wednesday night. So this is day 3. I just candled some of the eggs because I'm impatient to know if they're actually alive or not! I can see a big blob inside which moves about when i turn it, no veins as far as i can tell but the light was shining in my eyes and making my vision blurry so that didn't help! I can also see the air sac which looks quite big.
What is the big blob I'm seeing? Is it the yolk or the developing embryo? Or is the egg bad?

 

[gimmie birdies]

day 3 is a bit soon- by day 5-7 you can see better day 2 below
day 3 below

day 5/6 below

day 8 starts to get dark

day 18 all egg is dark but air cell.

 

[Demidog]

Fantastic, thanks