Newbie - Banded 2 weeks

Hi, I've been banded for alomost 2 weeks and I am a little worried! I
keep hearing about PBing and only being able to have a couple of
bites and then being full - this is not my experience!! I measure
everything - except water - so I know I'm not eating too much but I
do not think I feel full. I can drink a glass of water fairly
quickly without any difficulty - and I think I have felt hungry - I
say think because maybe its just pain or gas i feel. Is something
wrong here? Im just terrified that i have a non-working band or that
i somehow stretched my pouch. Has anyone had this experience? I
guess i shouldn't complain since im down 18 lbs - but i think my
first PB i will rejoice just because then i'll know my band is up and
working! Can anyone help alleviate my fears. Much appreciated!