[NOTE]If you have lost or found an Apple product, please contact your local law enforcement agency to report it. Although Apple does not have a process to track or flag lost or stolen product, you can use My Support Profile to find a list of serial numbers that have been purchased or registered with your Apple ID.
Go to My Support Profile*.
Sign in with your Apple ID.
View your purchases in "My Products".
* Currently available only in certain languages.
Note: If you need help remembering your Apple ID(s), go here.
Additional Information
If you have already configured the iCloud Find My iPhone service on your iPhone, iPad, iPod touch, or Mac you can use it to locate your missing device, display a message on its screen, make it play a sound at full volume (even if on mute), remotely lock it, or remotely wipe (erase) it to protect your privacy. Please see the following articles for more information:
iCloud: Find My iPhone overview
iCloud: Troubleshooting Find My iPhone, iPad, iPod touch, or Mac
If your mobile device is lost or stolen, see this article to find your iTunes-purchased files.[/NOTE]