Taking exams, for many people, is stressful. My experience has been to pretend the test is actually the week before and study for it then. It takes time for all of the new information that you've learned as well as previously learned material to be processed - what I like to call "letting the dust settle." Then, a few days before the test, review all the material a few times and make what I call a "last minute review sheet." This is simply a review sheet of the most important details/formulas that you'll need. Get a good night's sleep before the test and the morning of the test, read over your "last minute review sheet" a few times. If you practice this approach, you'll be more settled, rested and prepared on the actual day of the test.