4lbs in 10 days works out to almost a stone's loss in a month; well worth it I'd say!
The early stages can be tough, stick with it, ride it out, and you'll be so happy you did in a few more weeks' time.
Like the pp's said, it takes time for your body to adjust, everyone is different, and you will only lose as fast as your body is prepared to.
And who knows, next week you might lose double that (it happens!)
If you can't get packs, stick to low/no carb foods over the weekend a-la Atkins diet, get them next week and get back on with it.
You'll love the changes in yourself once you've been doing it for a few weeks, let alone the difference you'll see in a couple of months (if you even need to do it that long!)