You're probably ready but I would take a bit of extra time until you feel more confident. It sounds like you're confidence may be a little shaken at the moment. You don't want to panic during the exam and fail because of nerves. I've passed a couple of CLEP exams and multiple DANTES and haven't filled in the answers on the flash cards; I answer in my head. As long as you're getting around 85-90% of the flash cards correct you should be fine for this test. Do you know if your universtiy requires the essay or not?