Even if you have successfully placed a pre-order at Sam's Club for Apple's iPhone 4S, there is only a slim possibility that you might actually get one on Friday.

According to a report in Geek.com, Sam's Clubs nationwide haven't received the iPhone 4S shipments they expected for Friday's launch. A Sam's Club representative has confirmed that the chain was notified by Apple that initial iPhone 4S shipments would not be arriving as expected.

The store executives said they had no confirmation regarding how long the delay was going to be, indicating that it could be a matter of days or weeks.

Sam's Clubs intend to compensate for the delay and are offering a $25 gift card for those who placed pre-orders for launch day.

The newest Apple offering will be available at Apple stores and retail locations for the three carriers offering the device: AT&T, Verizon Wireless and Sprint. Retailers Best Buy, Target and Radio Shack have also received a shipment for Friday's launch. But queuing up in front of Walmart may not be a great idea, since their representative has reportedly said that his store hadn't received a shipment for Friday's launch.

The Apple Web site has already sold out the launch day pre-orders, limiting the options to retailers on the eleventh hour. The prospects of actually getting an iPhone on launch day, by pre-ordering online at AT&T, Verizon Wireless, and Sprint may be thin due to almost a week's delay in shipping.

Sprint's stock is limited to the 32GB and 64GB models and the carrier has said it will do our best to ship in three to eight business days.

Radio Shack is also out of launch day pre-orders and has reportedly told Geek.com that they have no more stock for Friday. But customers who pre-order now are likely to get one by Wednesday or Friday of next week.

If you are really eager to chat with fellow Apple fans all night in a queue, head to Best Buy right away. The iPhone will be sold on first-come first-serve basis, as the pre-orders will be applicable only after they exhaust the launch day stock.

Those who are pre-ordering the iPhone need to decide between the options for pre-order with delivery or pre-order with stand in line.