Hmmm, I don't think you goofed, but I do think you may want to re-think your file strategy. Is your main hard drive an SSD? If it IS, then maybe all is fine(though it rubs me the wrong way
). I prefer to keep all my sessions on a separate hard drive from the OS. Some of this is due to old habits(in the days gone by(with spinning hard drives), Pro Tools systems always recorded to a separate drive(or two) for performance. These days, a good SSD can allow you to have everything on a single drive, BUT, do you really want that? Of course, if your main drive is a spinner, then you absolutely want to have your sessions on a separate drive, for performance
While you think about how to answer that, creating full copies of sessions is a wise thing to do(actually....TWO copies) and these copies should be saved to separate hard drives(regardless of drive type). The idea is to have any session you don't want to lose, exist in at least 3 places(separate drives, certainly. And 1 of those drives should be stored in another building, in case of fire)
I know PT defaults to this location in Preferences, but I always(as in ALWAYS) change that setting to prompt for me to choose where sessions go(and for me, that place is a separate drive).