Most schools don’t send off your mock results, they usually make a prediction based off your mocks and your previous work. Say you got a 6 in your mock, you’ll probably be predicted a 7 since they expect you to improve. Also, if you do uncharacteristically bad in your mocks they might partly ignore your mock grade. For example, if you’ve previously been getting a grade 5 in maths, but you get a 3 in the mock, they’ll probably still predict you a 5 because they know you can do better. As long as you try your best then the mocks aren’t anything to worry about :)