I met this sentence in a TV series called Daria.

I am not even supposed to be taking this test. I am exempt.


My first question;

I do not have to take this test. This sentece and other one have the same meaning?

And another question;

''Be taking'' is grammatical? Is there a difference between these sentences:


I am not even supposed to be taking this test.

I am not even supposed to take this test.

Thank you for your help.