i need help with coyurnix eggs

[junior123456]

I candled my 12 day old coturnix eggs and 40 of them look black light cant shine threw the egg but I cant see the vains in the eggs its just black does this mean theyre not going to hatch

 

[James the Bald]

Sorry for the delay. Not seeing any light shine through means that there is a chick forming inside. I've never had any luck seeing veins at day 7, so I normally just candle on day 14 just before lock down.
When the light shines completely through on day 14, that means the egg was infertile and there is nothing inside. Here is a link for hatching eggs that will be of some assistance.
James