Hi,
That sucks.
It might be related to how clusters often strike when our stress levels drop and we move into a more relaxed state. I rarely get bad attacks at work, or out socialising, because (I think) I'm worried about getting an attack then and my stress levels are slightly higher than normal. But when I get home and relax, or sit down to watch a film or chill for the weekend, BAM! attacks come then. Some have said they dread holidays because as soon as they arrive at their hotel and relax, they get slammed.
But, I also think hormones have a lot to answer for in cluster attacks, so may be hormone related.
Or just a perk of being you.
Hope the bust goes well.
Mox