How many sessions have you been attending?

Hi there,
I don’t know how to put my question when “I want to ask about the number of sessions covered in a class.” Is that right to put it like:
How many sessions have you been attending?
Isn’t there any better idiomatic one?
THX

Can you explain your question again? I can’t really understand what you are asking.

I mean, what possibly could an appropriate question be when the answer is:
" It is the 9th session of this class"?