i'm totally natural myself, plan on staying that way...but in the few times I've had my bodyfat read (always by those pinching calipers) it has read consistently below 16%--once 10%, more recently 13-14%. Yet I have always had regular periods even when I was skinnier than the 10% (in high school i was a stick). The point is, is this low bodyfat okay if I'm still regular? Don't want to be losing any bone mass.