Well, I've heard that in smaller people, such as yourself it takes much less time for it to exit your body. I was wondering the same thing, because I'm 5'11" and 122 lbs and I thought it would take at least months since I've been a daily smoker for years, but I was told that it would only take about a month because of my weight. I'd assume the same would apply to you, getting out of your system faster, but I am no doctor or expert on this matter, so take it with a grain of salt.