Single cream/yellow coloured eggs on brassicas

I have found some little eggs on my caulis. They look like cabbage white eggs but there is only 1 egg in any location (not clumps). These single eggs are on either side of the leaf. Does anyone have any idea what they could be?
I did see some very tiny creatures that looked like ladybird larvae but they were incredible small and quite hard to see so I can't be sure.