I have 1 more question.... I have a egg that already was incubating before I got it and I have no idea how far along it is. It is a bantam egg and I think it is on day 16 but how do I know? My other egg is on day 18, should I put it on the same schedule?
you candle it and watch growth. See end of message.
As for part b... You are between a rock and a hard place. Scenario a, your day 18 babies all hatch and you get them out and put 16 in by itself to hatch. Scenario b, it's actually a 17/18 and it comes out with the 18 babies. Guess right and your good, guess wrong and you risk birth success...
If it were me... Two are hatching "sunday", one "tuesday" and 6 "sometime" (what i gather from your posts, but all are relative, our first 9 took 30 hours from first hatch til last) i would spend the next couple days candling Tuesday (not sure what you call this egg, but I'll call them: the twins, tuesday, and the others for this post) and try to find out exactly where that chick is in it's progress. Then put the twins in your hatchbox and keep tuesday with the others. If the twins are born before tuesday pips then you are golden, if that's the wrong guess, tuesday will birth with the others...but they will not have pipped yet, so you can try to let out small amounts of humidity when it skyrockets on you.
But back to the top there...candle tuesday and try to figure out where (s)he is in her life. If (s)he is ready for lockdown, his/her back should be against the pointy part of the egg and you should see feet and beak pointed at the air sac. The bird will slowly move up and make an internal pip before the external pip. Just do what you can to get him/her moved before the external pip without harming the twins.
Sorry for the messy message, its early here!
Ryan.