What to do?

[Birds Buns and Pigs]

So I've been incubating button quail eggs. I candled them a while ago and out of 12 eggs, 6 had clear veins in them.
It'll be day 19 tomorrow, what do I do? Leave them longer, or crack them open? How likely is it that they will actually hatch

 

[Chick-N-Fun]

If there are only 6 viable eggs, then I would remove the others in case they explode and compromise your hatch. Good luck!!!

 

[nchls school]

They should have hatched by now. Most likely not going to.

Any good egg would have candled completely dark except the air cell.

 

[Birds Buns and Pigs]

They should have hatched by now. Most likely not going to.

Any good egg would have candled completely dark except the air cell.

I candled them before lock down and they were fully dark with a clear air cell

 

[nchls school]

I candled them before lock down and they were fully dark with a clear air cell

That's good. Still... wait another day, but sorry most likely they are not going to hatch. Try again. Buttons are great little birds.