A chart displaying the most recent 7 filled entries. But I don't know how to make it.

I would like to create a tab in Excel where I can input weeks 1 through 52 and below that, input fields where I can enter data. Additionally, I would like it so that when I have, for example, inputted data for weeks 1 through 18, the chart only displays weeks 12 through 18, and when I input data for week 19 the following week, the chart automatically shows weeks 13 through 19. How can I achieve this?