As you probably realise, most of this 'added' weight is what is often referred to here as 'water weight' as I am sure that you didnt eat the 10,000 calories that would constitute an extra 3 pounds of fat!!
Hopefully if you stick to plan and drink your water you will see those 3 pounds vanish before too long.
One thing that caught my eye in your post. You said you would not eat after 5 pm - there is no real reason to do this, just make sure you eat when hungry and stop when no longer hungry.
Dr Atkins didnt make any rules about not eating after any particular time, so if you see you are approaching the '6 hours without eating' mark then have a small high-fat snack to avoid ending up being so hungry that you decide to eat the first food you see!!