I'm incubating for the first time, and I have 14 silkie eggs. Today is day 7 and I candled then for the first time. I'm pretty new to this, but I've done a lot of research and I believe one egg wasn't fertile as I see no development and one looks to have a blood ring. How long should I wait before discarding them? I'm kind of worried due to my lack of experience I'm not reading them correctly and I don't want to remove them from the incubator if they're actually ok!