Go to this link to get familiar with what normal development looks like. Blood rings are very distinctive rings. Veining tends to look more random. But, if you aren't sure, mark it with an "x" and look again in a few days to see if it has changed.
https://www.backyardchickens.com/th...ng-pics-progression-though-incubation.261876/
https://www.backyardchickens.com/th...ng-pics-progression-though-incubation.261876/