Haiku is one of the most important form of traditional Japanese poetry. Haiku is, today, a 17-syllable verse form consisting of three metrical units of 5, 7, and 5 syllables. In japanese, this convention is a must, but in english, which has variation in the length of syllables, this can sometimes be difficult.
i m watching,
rain out of the window
with a book open
watching rain through the window (7)
with a book open (5)
Not sure your syllables were right--as you mentioned--but who cares. Rules were made to be broken and the poem evokes that nice feeling of reading on a rainy day.