I checked my eggs that are due on the 23rd yesterday and could see good veins, movement, embryo, etc. So, they are on day 10. I also checked the ones due on the 26th and the different in development was pretty big. So I think tomorrow you will have a good idea of which are good or not. But of...
You should be able to see a bit more by day 10, but I don't discard any before 2 weeks or even 3. The spots can distort and block the light and you can't be certain. I would be patient for at least five more days before cracking or discarding any.