What was the property address? Did the listing have a due date for all offers, or was the agent submitting the offers as they were received. Each bank and asset manager have different time frames, but most of the time you would get a response within five days. I would call your realtor, and have them follow up with the listing agent. Some REO listing agents don't have the courtesy to tell you your offer wasn't accepted. If you have any questions, I would be happy to see if the listing is still showing active.
Coldwell Banker Coon & McCreary Realtors
1954 Contra Costa Blvd.
Pleasant Hill, CA 94523