There was no need to worry!

I was worried that by pruning the Buddleia in the spring instead of the autumn, I had cut off the flower bearing shoots - especially as it was later than usual showing any buds.
But, here it is - as beautiful as ever! 
Still no sign of the butterflies and bees, though. The butterflies tend to arrive in most numbers as the flowers are dying, but the bees are usually there from the start.