Ans) You may have cancelled the registration process halfway in your previous attempt. Thus in your next attempt the browser shows that selection.
So that's not a big deal at all, follow the below solutions -
solution 1) On the final checkout page you will see your total items list. Just click the cancel button provided besides every product item in the list and wait for the unwanted product to disappear from the list. OR
solution 2) Simply go to an incognito window and do the registration from there.