yeah it really doesn't sound like your appendix, it's a lot lower down that you're saying. plus it would have got a lot worse by now.
my friend had mystery pain in her side on xmas day and the doc at the hospital was convinced she had an ectopic pregnancy, and basically wouldn't believe that she was a virgin. numpty. but i doubt you have that either so don't worry! like hazy said you might just have a bit of trapped wind or similar.