Hello friend, thankyou for your question.
Incubation time for a canary egg is 12-14 days.
If you have a hen who has been sitting at least 3 days you can hold the egg up to a light .A new or infertile egg lays clear and the light goes straight through.
A fertile egg displays an embryo and the veins within the egg.
Eventually an egg that is fertile becomes opaque.
Here's a very good informative website you may want to read:
Let me know please if you have any questions?