Hmv hammersmith Apollo age limit?

I've ordered tickets to go to hmv hammersmith apollo to see The Wanted, me and my friend are going, im not 15 yet but by the time we go she would be 15, but I won't, and people who are 14 or under have to have an adult! So does that mean I have to buy another ticket? Cuz I don't want to :) I was thinking that they wont know how old I am so I should just walk in normally like I was 15? What do you think?