x2!
When you run without a fan you want the temp to be around 102F at the top of the eggs; There was a post on here last week in which the same thing happened. The eggs did end up hatching but were 3 days late. I would not give up hope on your batch yet but I would increase the temp. I would also make sure that you have at least 2 thermometers monitoring your temp. You can easily calibrate them and I would even do it now even though you are 2/3 through your incubation. If you search this site it will give you detailed directions on how to do it. Humidity is also important. Normally I say to use your hygrometer as a baseline and then go off of what your air cells look like. But since your shells are so dark you may never get to see your air cells.
In this case though I really do think your biggest problem is low heat. With that said thought, if you could see through your eggs you normally can visualize blood vessels as early as 3 days but most definitely by day 7.
With the BCM eggs that I am doing now, I do candle them to try to see growth, but even if I don't I will not toss any of these eggs unless they smell because they are hard to visualize. My normal hatch rate is between 87%-94%. Historically I have had difficulty hatching BCM eggs, and I have seen many people on this site saying the same thing.
Good luck!