Turnitin is just a guide for lecturers to see what is being highlighted and why. They aren't machines and will actually be able to see if something got highlighted that isn't an issue (e.g. a properly quoted and cited quotation, a properly formatted bibliographic entry, a cover sheet) vs something that may be (extended passages of prose with very similar structure and content to one or two other sources otherwise that you would reasonably have access to might start raising some eyebrows) and make a reasoned judgment about.
I'd suggest you also look through and see what was highlighted and think about why it got highlighted and if you think it's an issue, rather than just the end %. Note though that self-plagiarism is a thing so keep that in mind...