NEED HELP SOON!! TERM PAPER- VERY IMPORTANT

My term paper was due today and I did not finish it so I turned in my rough draft to my teacher. my question is do I wait for her to grade it and then say i had accidentally turned in the wrong paper? do i try to get it back from her? i dont know what to do. this paper is worth 20% of my grade. Also, I have turned in a few of my essays late this year so I dont know if she is huge on trusting me. what do I do????