Well, after a couple of set backs, hamstring twinge and a really heavy cold, I completed Week 3 again last night.
I know today should have been a rest, but I was desperate to know if I could run for 5 minutes non stop so went to the gym. I had decided I would just do half of the run, and build up from there, but I felt not too bad so kept going. Last five minutes was hard, but I made it.
In total, managed 4k in 30½ minutes. Might not be the fastest 4k ever, but it's a personal best for me!