Sorry, but there's just no way to predict if a hurricane/tropical storm will affect any given island during any specific week in September/October. The reality is during any given year there will be some 10 to 15 "named storms" and perhaps 6 or so will make landfall on or come close to one or more islands. Which islands, if any, are anybody's guess. The Atlantic/Caribbean is vast covering over 41 million square miles. The point being, even if there is a major storm brewing it may not come anywhere close to the island you are visiting. Typically a given island will experience a major hurricane every 3 or 4 years but sometimes they can occur more often.
You can research the historical frequency of hurricanes on any given island at
www.stormcarib.com - use the "Climatology" link at the top of the Home Page, then scroll down and select "Hits & Misses" then click on the island you are considering. You'll be directed to a chart showing the dates of every major storm that affected that island since 1851.
By the way, if a storm does visit the island while you are there you can expect a day or two of unsettled weather. After the storm passes chances are you'll experience some very nice weather conditions.
Now, all that being said, September and October are the peak month for storms which is why it is "off season" in the Caribbean. In addition to the risk of storms many resorts and restaurants will be closed.
If you do decide to travel at that time you'd be wise to purchase Travel Insurance with "Trip interruption" coverage in the event you have to cancel because of a storm.
