pretty little liars season 1

I am rewatching alll of the pretty little liars epsiodes from the begining of season 1 epsiode 1. The first thing that I thought of when started after the flash back was, Aria is the first person to get introduced.... BIG A? but then I realized that they would've had to plan that from the very very begining. But, if Aria doing the close up SHH in the theme song, they would've had to plan that too.... so maybe aria is big a. But, I personally do not want that to happen, because when I found out that toby was A I was shocked. And, if aria is A then I wouldn't be supprised.