I don't think I had the word of power yet. Since leaving Bleak Barrows I've gotten 2 words of power. 3 are needed or do I have enough?
Do not confuse the "Word of Power" with the 3 words that make up a full "shout", of which there are 20 shouts(I believe) in the game. There are words of frost and many others. Bleak Falls Barrow is the place that a "Word of Power" is found in a large cavern on a wall behind a crypt. Once you absorb the word, you will be attacked and the stone is on the body---as stated. Good luck.