Hey Locket, good to see you on the Atkins boards. Did you come straight across from dukan or have a break in between? If you came straight across you're probably not seeing any immediate loss because your body is adjusting to the new eating pattern.
On Dukan, a small slip up can stall or make you gain, right? I see people on that board being told that eating ham could have stalled them for a week, or who gain from eating Philly extra light.
So imagine if, while on dukan, you ate all the things allowed on Atkins for a day! I think many people would expect a stall or gain.
Your body needs to learn that this is it's new way of eating now and switch to burning fat - especially if you weren't in ketosis on dukan as I imagine most aren't. People think the two diets are interchangeable but really the only thing they have in common is a need to eat lots of meat.
Dukan is high protein, low fat, Atkins is high fat, medium protein.
So
Make sure you've dropped all your dukan habits . Make sure you are eating no yogurt, no skimmed milk but plenty of butter and cream.
No oat bran.
Make sure you're eating plenty of fat, protein at every meal and green leafy veg.
Make sure you're eating a decently high calorie level, 1200 daily at least.
What's probably happened is that you had a gain when you started Atkins and have now dropped that - which is a good start! Hopefully the scales will be going down soon.
Do be careful with the nuts. I would suggest no more than 30g a day and make sure you count the carbs.
Why not start a diary and post your daily menus? You sound determined and that's all you really need.
Good luck!