This is a probably a dumb question but I've never experienced this before. When I sit down and tighten my stomach it kinda moves to the front and becomes some...weird sort of line? It's feels really tight. Is that normal? Is it good? When I relax it goes away. I'm 14 going on 15 and I weigh 104.5. I've been struggling with weight since I dropped about 35 pounds in a year. My metabolism has been high and I don't really gain weight. I'm not really trying to lose weight anymore but it keeps happening. Maybe this has something to do with it?