I chose my office as the place to set it up because it was lower traffic and I thought I would be able to keep the temperature in the room stable with a space heater. Not true at all. The room was fluctuating by 20 degrees throughout the day/night and I couldn't get it to balance out. It was affecting the temperature inside the incubator and it's really important to keep it between 100-102 at the tops of the eggs, any higher and it could kill the embryos.
It got to frustrating so I ended up moving the incubator into the kitchen. That way the dogs/cats couldn't get to it, the temperature in the room never fluctuated more than 5 degrees and I could check on it frequently. After that it was smooth sailing. There were still hot and cool spots in the incubator because there wasn't a fan circulating the air, but the lowest was 99.5 and the highest was 103.2, with most of it in the right range.
At Day 7 I got to candle all of the eggs. Candling mean shining a light through one end of the egg in a dark room to see what was going on inside. You can buy a fancy egg candler but I made one out of a small flashlight and a toilet paper tube.
At Day 7 you can see a small spot with veins coming out of it. It looks like a spider. That's the baby chicken starting to develop! White eggs are the easiest to look into, but we have brown and green eggs so they can be a bit challenging to see into.
This one is a normal egg. You can see the air sac at the bottom of the egg, the embryo above it, and veins spidering out from there.
This one turned out to be unfertilized. The yolk moves around in the egg and there didn't appear to be any development.
Unfortunately quite a few of the green eggs from my flock ended up to not have been fertilized. I culled 7 eggs and I think 4 more are also unfertilized but they are hard to see in so I'm waiting until Day 14 to be sure.
I candled again at Day 10 and could see more development in the eggs. Right now of 47 eggs I can see development in 32 of them, 7 were culled, 4 have shells to thick to see in, and 4 I'm pretty sure are infertile but I'm waiting a few more days to make sure.
Here is one that is developing really well.