Is it normal to be scared of being seen by peers?

After taking an exam, my professor requires that we meet with the teaching assistants outside of class. I mistakenly went to the wrong room and did not realize until I heard voices from next door. I did not want to join them because I was obviously late at that point, and I did not want to leave to go home, for fear that one of the people there would recognize me from the class, and notice I was not in the session. I stayed in the empty classroom for around an hour, waiting to be sure nobody was left to notice me, not moving my legs or feet (shoes might squeak, giving my presence away) or unzipping my backpack (again, the noise). I just silently sat, frozen in fear, only able to tremble and use my phone to message my boyfriend about my panic.