Yeah, I must admit in all my years as a contractor I never joined a union - not sure what union covers IT contractors?
The only union I ever joined was the Musicians' Union (back in the early 1980s) which was a stipulation of my RCA contract (brag, brag).
Firstly, obviously I'm sorry for your predicament.
However if one of my new contractors emailed me a few days after starting and said they couldn't come in because their neighbour's dog had died (or whatever, not immediate family anyway) and they'd been up all night I would be mightily pissed...