BTW someone have made a list of all 2 week periods from April (hidden in 'Copy') here:
https://bitcointalk.org/index.php?topic=582736.0. You may see the list there.
Also 14 is the potential activity that you can earn in a 2 week period, no matter how many activity points you have. To redeem the potential activity just make enough posts, and if the post count is high enough, you will get 14 activity simply by making 1 post in a new 2 week period. (Remember not to spam posts to meet the requirement - or you'll be banned soon!)