How common is self-studying for AP Exams?

I’m self studying for several AP exams and taking the tests at a public school (I attend private school with limitations on course selection). The College Board allows this practice and the public school was fine about it. However, my school seems to be upset that I did not do this though the school/notify them. I thought self-studying was common and I’m a very ambitious student. I’m scared I’m going to get in trouble when I’m simply trying to improve myself.

Here, it seems pretty common. In the real world, not so much IMO.

I don’t see how. Although in hindsight, I would have registered for the tests through my own school, which is what I have done in the past. Either way, no big deal.

If your school offers AP exams, you should have been testing through them. They can order any exam regardless of what courses they offer. Each school has a process for requesting to take exams for a course you aren’t taking. Usually, you need to just pay the exam fee and the school will be happy to proctor it for you. For example, my high school offered the spanish lit and environment science exams, but did not have the courses, so everyone who takes those exams self studied. Testing at another location other than where you go to school is usually done only if the high school doesn’t offer AP exams or if you’re homeschooled.
I think you should have gone through your school, but there is nothing you can do now. They’re not likely to do anything about it.

Thanks!