small cucumber plants flowering and fruiting early

hi all, fairly new to this so any help greatly appreciated.
my cucumber plants (marketmore) are in the greenhouse all seem to be growing well, approximately 12 to 24 inch tall. just noticed some are flowering and setting fruit quite low down, some after 2 pairs of leaves some after 3 pairs, is this normal. should i pinch them out or just leave them. i started them off end of feb in house and are now in final position in greenhouse.
also courgette (green bush variety) are flowering too, sown at the same time and are now in large tubs on garden, is this normal too.
im just thinking is it due to the mild weather we have had in sheffield over the last few months being in pots i have been able to bring them all indoors when cold weather or frost.
any help greatly appreciated on both plants.

john