["I just KNOW I got an amazing grade on my last test... Can't wait to see it.", "That's such a great feeling! Congratulations on all the hard work you put in paying off!", 'Thank you! Yes, I am just feeling very sure of myself on it (for once haha).']
Then it sounds like you have two things going for you; an A+ and some new found confidence!
I just KNOW I got an amazing grade on my last test. I can't wait to see it.