There is sometimes a lag between when you buy and when it disappears from the cart. This is just in the notification area that says "one item in cart" usually if you just click the cart, it will disappear. If you look in the cart and it is still there, then just remove it.
As for your payment being pending..did you pay with a bank account, which means it will be pending for some days before it goes through. As for notification from eBay, sometimes they don't come through, or may come through later when your payment clears.
