idont know if my eggs are viable

[BaileyBoy]

Hi i built a homemade incubator and have turned my eggs twice a day for the past eighteen days, the humidity and temp have been spot on at 99 and 62. However, today is the 20th day so my eggs are on "lockdown". Before i put the eggs on lockdown (Raising the humidity and stop turning them), I candled my eggs, i didn't see what all of the charts say i am supposed to see. I think its a yolk floating in the middle. Some of them it doesn't move but some of them do. The reason i am confused is that there is now bad smell and my friend (a chicken owner) says that that is what happens and they ARE still viable. Any words of advice, or words of reassurance.
Also, these eggs are rhode island reds so i don't know if maybe they take longer or something?

 

[shmccarthy]

If the eggs are on lockdown age, 18 days, then the entirety of the egg except the air cell should be very dark, and you shouldn't be able to see the yolk. It sounds like the eggs are undeveloped or infertile, which can happen if you have a young or old rooster, or if you have a lot of hens. As for the smell I cannot say.

 

[aart]

If there's a strong smell, find the egg that smells and get it out of there...there's a chance that it could explode and you don't want that to happen!