TOPIC: Practice Exam Scores: Good Scores, but Decreasing Over Time

I started taking full practice exams about two weeks ago after studying the past four months. Here are the scores in order:

PM Prepcast Exam 7: 81.50%
PM Prepcast Exam 8: 80.50%
Head First PMP: 78.5%
Aileen Ellis: 76%
PM Study: 76%
Simplilearn: 73.5%

After each exam I review the wrong answers, revise my notes, etc. The scores look good, but they are decreasing over time. I was hoping to see more improvement over time, but I think I’m just very tired. I’m scheduled to take the exam next week Tuesday 12/5. I’m concerned about my ability to retain this information long term, and I’m wondering if it would be better to reschedule for an earlier test date, get a good night sleep, and take the exam.