should I harvest?

I have one of these bags from t&M which came with 5 seed spuds, i cant remember what types they are, but the have just finished flowering and the flowers have dropped off (they were purple) i dont know if they are first earlys, second earlys or main crop? Should i empty the bag to see what there is...the plants are so long (were high but now growing sideways  so i dont want to disturb them if they arnt ready.. i cant furtle without taking out a couple of the plants...