Are you working with a buyers agent? If so, he/she should address your concerns.
That being said, if you received a verbal acceptance more than likely you are good to go. The REO brokers and their clients (the bank) are inundated with paperwork and it sometimes takes longer than "usual" to get the documents to the buyers for the signatures.
If it's been more than 5-7 business days since you've received the verbal acceptance then definitely check in again and don't let Friday come & go without some sort of communication.
Have you checked the status of the listing in the multiple listing service? Feel free to use my website to check. It is directly tied in to the MLS and updated regularly. It should say "pend, or A/I, or SS or ctg", on my website it will say "under contract".