Hey guys, this has been happening for couple years now, I really didn't pay much attention to it as it really didn't affect me physically.

Here's the situation, I would weight my self every week, and each time I weight my self there will always be a 5 pounds difference every week. I'm a slim guy. At the moment I weight 140, but if I go weight myself next week, it'll be 135, then back up to 140 the week after, 135, 140 ect.

Over the years, this happened just about every week, I can't maintain a given weight.

120,115,120,115,120,115,120,120,125,120,12 5,120,125,125,125,130,135.....

I see a pattern like that for the last couple years, never really take notice as it really didn't concern me, but I'm just wondering if it's normal? I'm 17 now, so maybe puberty has something to do with it?

I ask this question because I'm a little concern that I might have parasitic worms, or maybe an over active imagination?