I bought eggs off ebay and almost all were fertile. Those that were developed nicely up to about day 14. Some quite before that. At day 17 I checked them again and all but 3 seemed way under developed. Like they never got past day 12 to 14. No movement or life it seemed. On day 18 just before I locked down I was able to see 3 chicks moving. One egg was almost completely black (that is what you want right?) and the other two were alive but seemed to be much further behind. I saw them moving around in there though! One has a strange air cell, like it is on the side sorta. So-I'm on day 23 and still nothing. I've got constant temps and my humidity is up around 70-80. Any thoughts on how long to let them go? Should I check them? This is my first hatch so any advice would be awesome! Thanks!