Coccidia poop is usually diarrhea, so those poops appear to be within normal range. As long as all the chicks are active and good appetites, I see no reason to suspect either worms or coccidiosis at this time. But do keep an eye on that poop for increasing amounts of intestinal shed. That...
How old are these chicks? Worms in very young chicks are rare. And that reddish substance is not blood, but shed intestinal lining which is normal to see on occasion.