I have had a look through some of the marking schemes on the AQA site. I am not sure exactly which exam you took, but the general pattern for the English exams seems to be to use descriptors. In this system of marking, the examiner chooses the band that best describes the student and givesd a mark within the parameters. With this, then you are unlikely to lose much as the emphasis is on the degree of skill with which the task has been handled. If the contents are good, you should be OK.
Good luck
