only 3 days? Give it the week. Your body is just starting to figure out you've changed the way your eating. If your eating 20 or less carbs, you should be fine. Dont worry about the scale just yet....put it away until the full 7 days are up, check to make sure everything is going down, and get on with the next week.
Watch out for diet sodas, sugar free items, and sweeteners. These will very likely stall out your weightloss.
Good luck to you, pop over to the Atkins dailys and say hi and hang out.