If you’ve done three shifts over 13 hours (which you have), you’ve used your three reduced rests so your next shift must be a full daily rest of at least 11 hours, meaning you can be at work 13 hours as an absolute maximum.
Remember as you work 4/4 your run of days in will sometimes split over two weeks ie Fri, Sat, Sun, Mon in work. It doesn’t matter as the rules say “maximum three reduced rests BETWEEN TWO WEEKLY REAT PERIODS”