Yeah I'm not built thin either. I was at my current weight 2 years ago but that was because I was on Atkins then too and working out (which I do now again too). I quit and got up to 162 and I hope to get down to 130. This time I am better at it and I actually like it. Let me get out my calendar and I will tell you when I reached 150. Okay, it went like this:

Jul 1: 162
Jul 7: 157.5
Jul 14: 156.5
Jul 21: 155.5
Aug 12: 154
Aug 19: 152 (1 1/2 to 2 months to lose 10 pounds)
Aug 26: 150.5
Sep 26: 146
Oct 24: 145
Nov 9: 143
Nov 24: 142.5
Nov 30: 140.5

Everytime I lose a pound, I go back up a few pounds for around a week and sometimes a few weeks then I lose those few pounds back plus another 1 or 2 within a few days. So I go down then up a little then down even more, etc, etc. It gets frustrating cuz it feels like I gain right after I lose but as long as it's going down in the long run I don't care. I don't want to weigh myself everyday or even every few days anymore though. Good luck, you'll definately get there.