You could TRY 2 steak days in a row but USUALLY the 2nd isnt as effective as the first.
If you have gained weight like you say 5-7 pounds then you need to exercise and watch what you eat. You of course could always do a 15 day round, but its good to learn about your body and try to maintain on your own. If you still gain then do a 15 day round and in the meantime try to figure out where your going wrong in your eating and exercise habits.
Hope this helps!
Misty