Are you using the exam simulator, and have you taken any of the full length tests? What other study resources are you using?
I wrote on June 26, but I spent the last few weeks just taking the 4hour tests with the exam simulator. I scored 74% of the questions answered correct on the first pass. I still felt nervous about the exam.
I would say if you feel that you are not prepared, the pay the $70 and reschedule. Spend the next few weeks taking the test so you are comfortable with them. I found the exam simulator tests more difficult than the actual exam, but that is just my opinion.
It is important that you feel confident and prepared, and practice as much as you can.