CHEERING for you and CHEEPING for the chicks!!! Ya! Congrats! Your story makes me hopeful that my next batch will go better than my last, which was CRUSHING to lose!
Yay! See, the little guys...I mean--girls... are really tough! You might get a really good hatch.
Regarding temperature readings...I wouldn't worry if your thermometer reads below 102 F, especially if it's not an extremely accurate one. The eggs can survive more temp variation when they're about to hatch & are all the way developed.
I bought a very accurate Brinsea probe thermometer, which has been reading various different temps, including 98 against one hatching egg in the carton in the 'bator, and 102 against the shell of another one on the other side, and they all 15
100%, hatched out okay, even with the the temperature spike they went through when I first put them into my hatching 'bator.
Don't give up on any stragglers who haven't hatched by Day 21 either. SOme may take a little extra time.
I hope you post some pics of them, we'd all love to see them