Body Fat Percentage

I found out from my friend Michelle that I can get my body fat percentage tested at our gym. I'd been curious to find out what it was...supposedly our scale here at home will tell me, but I couldn't figure out how to get it to work. I'll be honest, I was a bit nervous what the number was going to be, but I told myself as long as it was under 40% I'd be happy. I really had no idea what to expect and wasn't sure if that was a high enough number to pick. The guy who tested it was kind of an ass hat--you know the type, douchey jock sales guy--but I was pretty pleased with the results. It came out as 27%! I didn't think that was bad at all. It fell in the "fair" category when he busted out a chart that showed what numbers meant what for age ranges. I thought that was decent. I'm not sure how often going forward I should check it, maybe once a month?