Dull Ache in Right Abdomen

Hi, I've been having a dull ache in the right side of my abdomen for maybe 3-4 months now. It isn't actually pain, in the sense that it "hurts," but I can definitely feel it. If you start from the belly button and move right (medical perspective), that's where it aches. It happens whenever I move, especially when I'm stretching. Actually It's kind of hard to pinpoint exactly where it is. My lower back often aches at the same time it is.

The thing is, I am 18, and the past year has been pretty stressful. I stopped exercising and went from 140 lbs to maybe 160 lbs over the course of 5-6 months. Naturally, I just attributed this pain to "becoming fat." Now I'm trying to figure out what exactly this is. I spend a lot of time in front of the computer. That might explain the back problem, but not the side ache. Can anyone help?

[Dimidine]

Exactly my feelings too. Also spend time on computer too.

[JJJ92]

Although this feeling sort of constant, I've noticed that it gets progressively worse throughout the day. For example, I spent my day fine today, and now at 9:00 pm, I'm starting to feel it enough that I would make this post.