First Time- Candling Help Please

Okay, so it is my first time hatching. I've got 14 shipped Dark Brahma eggs in my Brinsea 20 Eco incubator. It is day 4. I candled when they first got here, most of them had detached air cells. Let them sit 24 hours before placing in bator. I candled tonight, mostly out of curiosity. In all but one egg the air cells have stabilized. However, I saw no development in any of the eggs. There was a dark spot at the top (the yolk I think?), some had dark pieces swirling around. I saw no vascular structures, nothing that looked like an embryo. Are the eggs no good? I can't get a picture I'm afraid, my candler is the light on my phone. I'm afraid to open them if there is a chance there is a growing embryo inside. But shouldn't I see something at this stage? Help please!