While it is unlikely that your exam has been scored incorrectly, it's not impossible. There could be a very rare computer malfunction during scanning, or you could have used the wrong type of pencil when filling out your answer form.

Is a 3 on an AP test bad?

An AP® score of 3 is a respectable score. The College Board designates a 3 to be “qualified”. That means that you understood and executed the material to the point that you could pass the college class. While you did not receive the highest grade in the class, you did pass.

Do colleges look at failed AP scores?

Basically, nothing happens if you fail an AP exam. Whether you get a passing or failing AP exam grade, you can still go to college. Colleges do not take a look at the AP exam as the only a criterion for accepting or rejecting a student.