Ok a couple things to help you out - standard double spaced manuscript in publishing is considered 250 words - ignore work counting programs. If you are writing 2500 words you should get a whole lot more than one or two pages.
Next as to the reason, i suspect you stories do not contain much color and are little more than a fast sequence of events - it would help if we had an example of your writing but for sake of illustration here is an example of what I suspect is happening.
First what i think you are doing
Anna ran down the passage and burst into the sleeping charger walking Helen, You must flee! They are going to kill you!"
Now what you need to be doing
Anna moved as fast as she could in the dim light. The cold stone had nothing to do with the chill than seemed to turn her blood to ice . It was the overheard plot to kill the Royal Family and Princes Helen was in her care. She had to reach her first, duty demanded it but self preservation nagged at her.and undermined her resolve. If she was there when the assassins arrived her life could be forfeit servant girl that she was. The stone was uneven and she stumbled as she ran and slowed slightly, knowing she could help no one if she fell and broke something. It seemed forever before she reached the royal bedchamber of the Princes and she rushed to her bedside.
You see the difference in the two. Obviously with more a two minutes I could make a paragraph that was more detailed but you understand that when stories are short they may not convey the actual color or emotion of an event
However - short sentences and stories sometimes are very powerful IF designed that way...