Losing weight unintentionally...

Hey,

I was just wondering if this is something I should be concerned about or not. I've been working out with fitness blender for probably less than 2 years, but I've been consistent. I'm not "all out" or anything, though - I only workout 3-5 times a week, and I eat moderately healthy (but I mean, I don't pass out on dessert, y'know? ;)) yet my body has been changing dramatically over the past year or so. I was already called skinny before, but now I'm more toned, more slimmed down in certain areas and have rather little amounts of fat on my body. I've lost 7 kg over the past year, without meaning to lose weight (I thought I would gain it, because I've certainly got more muscle!) although you really can't tell too much, because my body seems to have a way of hiding whether I gain or lose weight on my body (I guess it has to do with fat distribution.)

My question is, should I be concerned about losing 7kg (when I was already skinny, and I did it unintentionally)? I promise I'm NOT starving myself. I have been having trouble with my stomach though, but my GP says I have too much hydrochloric acid in my stomach, so I've been on tablets and that seems to have fixed it.

(At the moment, I'm 5'4" and I weigh 47kg.)