I think that supervisors in general recognize that progress is uneven--sometimes two steps forward, one step back! The main thing I think is to show SOME sort of progress, work in progress, thought in progress, whatever it might be. I stick firmly to deadlines for turning things in--even if the "thing" is not in the shape I wanted it---it might get sent with a disclaimer that it is being sent "as is" and that there are areas where I have questions, need more work, or got stuck...and highlight those as possible discussion points.
Some self-reflection or self-awareness and so forth in disclosing where you feel like you need to boost up the work might be appropriate? Perhaps depends on your field, your supervisor, and your comfort level with the material and supervisor?
Let us know how it goes!