A few things to look at/ think about.
1. Sounds like the two pounds you gained may be a short term blimp. This could be caused by a number of things, but my guess is that you had a high sodium day which caused you to retain water. My suggestion is to not weigh yourself so often (once/week is usually the recommended amount) and on weigh-in days try to be as consistent as possible in the time of day you weigh yourself and your food/water intake in the 24 before you weigh in.
2. Like Mecompo said, as you lose weight your body is burning fewer calories both at rest and when moving. At 2588 calories and 228 pounds, you are probably close to breaking even unless you are fairly active and are exercising on a regular basis.
3. How much water are you drinking? I really am a believer in drinking plenty of water to lose weight. I have had good luck drinking at least 1 ounce for each 2 pounds of body weight (which for you would be 114 ounces)
4. I know it is a challenge on Atkins, but I would try to find a way to get more fiber.
Male 45, 5'6"
To date - 32.6 lbs down
Start: 20 Oct 2011: 210.2lb
, body fat =35.3%
Original Goal: 20% body fat - achieved 3/1/12
Last weigh-in: 3-May-2012: 177.6
Last body fat measurement: Oct 15,2012: 14.1%
Goal: Maintain < 20% body fat and < 180lb
Days Maintained : 427