I’m glad you caught that on your incubator thermometer. Those things are unreliable. Although many incubator instructions say to not trust the thermometer they send with it, many people do and have real problems with their first hatch. You are way ahead of the game.
I agree about opening the incubator during lockdown. It is possible that you can harm the chicks by opening the incubator after one has pipped, but it is also quite likely you will do no harm. I consider it good practice to not open the incubator during lockdown without a very good reason, but if there is a real need, go ahead and do it.
I use this to add water to my incubator during lockdown without opening the incubator. I go in through a vent hole and can reach every reservoir with this. You can get the accordion straws a lot of places. Try to use a tape that water doesn’t bother. I got the syringe at
Tractor Supply but there are other sources.
Amylynn did not leave out a lot. A chick absorbs the yolk before it hatches so it can live for three days or more without any food or water. You don’t have to be in a hurry to get them out.
That 21 days is a general theoretical target, often not hit in reality. There are many things that can cause an egg to hatch early or late, heredity, humidity, how and how long they are stored before they go in the incubator, and just general differences between each egg. A real big effect can come from average incubating temperature. If the incubator is averaging a bit warm, they can be early. If it is cool they can be late, maybe two or even three full days off.
I’ve had hatches a full two days early under a broody hen and some right on time. I’ve had the same variation in my incubator. Many of my hatches, broody or incubator, are over within 24 hours of the first one hatching, some drag out more than two full days and nights. In a recent hatch I had one chick totally hatch a full 24 hours before another egg even pipped, then the other 22 came out with 24 hours. Each hatch is unique. Patience is usually your friend.
Have your brooder set up and running about a day before you think you will use it. Bring it up to temperature and ensure it is working right before you need it.
That’s about it. Hatch is a stressful time, not only your first time either but it gets better with practice. You are dealing with living animals so things don’t always turn out the way you want, but usually it does. Good luck!