Incubator Fluctiuating?

[MadamPoofyBrow]

I've had eggs incubating for about a week now, and just candled and they are CLEAR as if they weren't fertile, but it's basically impossible for them ALL to be infirtle since my roosters are pretty busy...constantly...
The temp has been fluctuating within like .4 degrees. Could this be the problem? They aren't showing any signs of early embryo death, they're just clear.
Thanks!

 

[eggbert420]

.4º not a problem.

 

[MadamPoofyBrow]

I thought not. Any idea what it could be?
It is changing within .4 repeatedly throughout the day.

 

[eggbert420]

Its normal, and .4º is very good. Most fluctuate 2º.