You don't say how old this tree is, which is helpful to know. Has it born fruit before?
Regardless, the stress of the move doesn't help. The big root ball was an excellent idea but you still lose masses of fine feeder roots in any move. As long as your tree is leafing, I'd leave it for this year regarding fruiting as it's just too much to expect. Keep watering and feeding with compost and some manure but nothing with high nitrogen as this will stress the tree even more. By next year it will have settled in with more feeder roots and likely produce crop.
Then you need to consider variety as not all apricots are self pollinating and hopefully you know what you have. This bit is from Colorado State Univ Extension and I know many varieties are available in the UK:
Peach, Nectarine and Apricot
The common varieties of nectarines and most peaches grown in Colorado are self-fruitful. Self-unfruitful varieties of peaches are J.H. Hale, Earlihale, Hal-Berta, Candoka and Mikado (June Elberta). Most other varieties of peaches will pollinate these self-unfruitful varieties. However, Elberta is not a good pollinizer for J.H. Hale. Self-fruitful varieties of apricots are Tilton, Wenatchee, Royal and Moorpark. These will set commercial Crops without cross-pollination. Self-unfruitful varieties of apricots are Riland, Perfection and Rival. Any self-unfruitful varieties can be pollinized by any other variety.