ok............so I am incubating peachick eggs for the first time

and everyone says that hens so it best! but I dont trust my broody hens right now as they are all 1st timers

...........
SOOOOOO, I did an exparment about egg tempature... I took my tempature gage and put it under two different sitting hens... it measured 103.4 for one and 104.8 for the other.... I then took the tempature inside my bator (it is a Brinsea 20 Advanced) and I have hatched in it twice ........
the first time the tempature was factory set at 99.5 but the chicks were all three to five days late, so I bumped the temp from 99.5 to 99.8 and the 2nd hatch the small eggs started to peep the day they were due (I set pm and had my first peep am.... so maybe 12 hours late) and the average and larger sized ones took up to three more days for the last ones to hatch..... this time I have it set at 100.0 ..... as it seems to run cool but other wise is great and I had very good hatches in it and the eggs were even shipped....
(SORRY!

back to my point, when I took the tempature with the probe I used under the chickens it only read 98.8 at the outside edge and 99.0 in the center (at egg height)
So same probe and under the hens was 3-4 degrees higher....
The idea here was not for the actual tempature reading as they can be different from gage to gage .... but to see the different in tempature between a sitting hen and my incubator......
My understanding is that still air (which is what a hen would be....right?) should be set higher by 2-3 degrees than a forced air (which is what mine is)..... Am I Right Here???

but this still seems to me that my bator is STILL running cool..... or my gage is messed up .....
ANY THOUGHTS?????