really stuck - please help - adding choices after submitting

hi guys,
basically im really stuck with what i should do. i submitted my ucas form on the 11th of october and picked 3 medical schools and 1 backup. i have decided that i want to add one more choice to my form and i know i can do this through track. will my school ucas co-ordinator be notified of the changes? does my form have to be checked by my school ucas advisor again? will my other choices know that i have added a choice?