So I decided to calculate my body fat percentage today and I was wondering 18.13% is A) seemingly reasonable and B) too low? I didn't think it was quite that low and I know it's getting kind of close to being too low. I just used the one on HealthStatus.com (It uses the one created my the military )
I'm not sure which one that is but you can do some quick googling /reading into how accurate & reliable various tests are. Often they have quite a margin of error...
It never hurts to try again. "measure twice, cut once" as they say.