If you're nervous about taking that test, you're not alone. A lot of people get nervous when they have to take a test, but some of that nervousness can be alleviated by making sure that you're prepared.
Knowing the material thoroughly can go a long way toward helping you feel more confident.
Other things you can do include making sure that you have eaten and gotten enough rest, not worrying if you aren't the first student finished with the test, forgetting about the test once you turn it in and not obsessing about it, remembering to breathe during the test so you don't hyperventilate, which can make you panicky, and analyzing the test when you get it back to see how you performed on it. You can also set up a strategy to help you get through the test, but you must make sure you follow through with that strategy or it won't really help you that much on test day.
Following those seven tips will help ensure that you do as well as possible on your test.