Does taking communion break the fast? Is there a Scriptural or Traditional case to be made either way? Now, once, I was fasting. I was destined to fast for three weeks. Now the church that I went to had Communion once every month, and it happened that my second last Sunday of fasting was my church's Communion. 

Does taking the communion break my fast? If so, should I leave from taking the Communion? Is fasting a "good enough" reason?
Per @awe and @Jamess, there are really two sides of this.  It can go either way.

Are you breaking your fast?  Yes.  You truly are.  But you have to question: Why am I fasting?  

If you are fasting in order to grow closer to God and find reliance only on him, then taking communion would not necessarily be bad.  Since communion is meant to draw us to God, then the two acts (fasting and communion) are moving towards the same purpose: moving us closer to God.

If you are fasting, however, in prayer over a specific thing (such as the salvation of a person or deliverance from a trial), then you should avoid the fast.  The purposes of the two acts (fasting and communion) are at odds.  

Having said all of this, I believe this verse is appropriate to the subject:

1 cor. 10:31


  31 Whether therefore ye eat, or drink, or whatsoever ye do, do all to
  the glory of God.


If you chose to break fast for communion, make sure you do it for God's glory.  If you chose to skip communion for the fast, make sure it's for God's glory.  If you follow that advice, you won't go wrong.