I’ll ask a silly question, do you have a rooster? This is actually come up before, that’s why I ask.
Do you have any experience candling? Darker eggs, especially green eggs, can be really difficult to see inside. Have you cracked any of them to confirm they are not developing?
Have you looked for the bull’s eye? If you crack eggs and see the bull’s eye then the egg was at least fertilized. If the ones you crack are fertile, the ones you don’t crack should be. This thread has photos so you know what you are looking for.
Fertile Egg Photos
https://www.backyardchickens.com/t/16008/how-to-tell-a-fertile-vs-infertile-egg-pictures
Have you calibrated your thermometer so you know it is working right? Not all thermometers read the way they should. These links can help with that.
Calibrate a Thermometer
http://www.allfoodbusiness.com/calibrating_thermometers.php
Rebel’s Thermometer Calibration
http://cmfarm.us/ThermometerCalibration.html
Rebel’s Hygrometer Calibration
http://cmfarm.us/HygrometerCalibration.html
In general, if eggs die in the first week or don’t develop at all, it’s because of something that happened before the eggs went into the incubator. It could be that they are not fertile to start with, or that they got so cold or so hot the embryo was killed. If they are shaken up really bad they won’t even start to develop. I did that once with eggs I picked up on a really rough country road. How long are you storing them and what conditions? Usually you can store them for a week without any real problems but after that the hatchability starts dropping unless they are stored in a relatively cool place. Storing pointy side down or on their side and turning them helps but shouldn’t be too critical the first week. You should at least get some to develop.
Check your thermometer and crack a few to look for the bull’s eye. Those are the two I suspect. If those are OK look at how you are keeping them before incubation starts. You should at least get a few to start developing.