Inchloss to Date

So I started my weightloss on 24/01/2012.

Because I don't own scales I've been working off measurements, although I do know how much I weigh. I have been measuring myself every two weeks. I have been measuring the areas which I would most like to see change in!
I'm now on week four, and this is what my stats look like:

Starting Measurements
Bust - 46" [wk2 - 45"] [wk4 - 44"](-2)
Under Bust -38" [no loss to date] (-0)
Waist - 36" [wk2 - 35"] [wk4 - 34.5"] (-1.5)
Midrift - 45" [wk2 - 43"] [wk4 - 42"](-3)
Hips - 54" [wk2 - 53"] [wk4 - 52"] (-2)
Left Leg -30" [wk2 - 28.5"] [wk4 - 27.5"] (-2.5)
Right Leg - 30" [wk2 - 28"] [wk4 - 27"] (-3)
Left Arm - 14" [wk2 - 13.5"] [wk4 - 13"] (-1)
Right Arm - 14" [wk2 - 13.5"] [wk4 - 13"] (-1)

Inches Lost
Total Inches At Start: 307"
Total Inches At Week Two: 297.5" (-9.5)
Total Inches At Week Four: 291" (-6.5)
Total Inches Lost: 16"

My question is, I guess, does this seem doable to you? 16 inches all over in four weeks? I have dramatically changed my diet into healthy, cutting out carbs as much as I can, eating a lot of greens, no bread or potatoes if I can help it, and I've also been working out on my cross trainer about 15/20mins a day, and so many people have told me they can see a difference, but I just wanted to check that this is actually doable and I'm not going wrong anywhere!! haha.

Sorry for the monster post, thanks in advance.