Drivers hours dilemma

Quick one, i,m having a dumb moment. I haven’t worked a weekend shift since before Christmas, so it’s been mon to fri for the past 2 months. However, last week i worked mon, tues and wed. had at least 36 hours off then back behind the wheel 10 am fri. Run to wales, back to teesside then run to essex back to teesside, knocked off 10am Sunday morning. Back behind the wheel 10am mon. When do i need to take another weekend break? Is it thursday?