Usually patience is your friend in these circumstances.
Since it is your first hatch I'll ask a silly question, did you count the days right. You'd be surprised at how often people don't. An egg does not have a day's worth of development when you stick it in the incubator or under a broody hen. It takes 24 hours for it to have a day's worth of development. So you say "1" the day after you set them. An easy way of checking your counting is that the day of the week you set then is the day of the week the 21 days is up. If you set them on a Tuesday the 21 days is up on a Tuesday.
That 21 day thing is just a guideline anyway. It is not that unusual for eggs to hatch a full day or even two early or late. There are a lot of different things that can cause that: heredity, humidity, how and how long the eggs were stored before setting, and just differences in the eggs. A big one is temperature. If the average incubating temperature is a bit high they can be early. If it is low they can be late. Not all thermometers read accurately. I don't trust those factory pre-sets either. If yours are a tad late it may be that your temperature is a bit low.
It can be hard to know when the hatch is over. I've had some hatches under a broody hen or in the incubator be over within less than 24 hours of the first one hatching. I've and some under a broody and in an incubator go more than 48 hours before the last one hatched. Since the chicks absorb the yolk before they hatch they can live for over 72 hours without eating or drinking. That's why they can be shipped successfully.
You don't have to be in a hurry to take the chicks out. In general if I go more than 12 hours (usually with an overnight included) without any activity like a pip or I see an egg moving on its own I take them out.
