As the saying goes: “Anything that can go wrong will go wrong”. Keep this in mind when preparing for the PMP Certification. It simply means that you should not solely depend on what others say about their experiences in taking the exams. Everyone's experience is different.
What you must remember at all cost is that you have prepared well for the exam and that you can do this! When you walk through the doors into the exam room, the most important thing for you is to pass the exam. You can partially achieve this by preparing yourself physically and mentally for the event. After the exam everyone has a story to tell. For example, one of my students wasn't allowed to change any clothing and the other one wasn't allowed to use the bathroom. These examples are of course extreme but they might happen to you.
So what if something similar happens to you? Take a deep breath. Listen to this "odd rule" that the testing center staff is informing you of. And then follow it. Don't jeopardize your chances. Play along and do the best you can. Adjust yourself mentally to the situation and work with it.
Remember: What really matters is that you relax, concentrate and pass the PMP exam.