When you place your order online or over the phone we obtain an authorization from your credit card company. This verifies that all information provided is correct and that there are enough funds to pay for your order. Your card is not charged at this time. Some banks may list these as pending transactions. Others will not show them at all. Once your order ships, the final charges are applied to your card.
If you see a charge as pending and then it goes away this simply means that the final charges have not been applied to your card yet.