ok, so seriously you have to stay off the scale if the number it says is going to make you adjust your eating when you get off of it. If you think yesterday was a dd then it probably was just go with that, you are in this for the long run and if you went over your dd by even a couple of hundred calories, it is not going to make that much difference. Regardless of what the scale says, ya dun good. Now enjoy your ud and plan for your next dd.
Have you visited the 5:2 forum? No need to join but there is lots of good info there...The 5:2 Fast Diet Forum | 'The Fast Diet' international support group very supportive group.