Put your Apple I.D. and password, and your MacBook Pro serial number in an email to yourself. As long as you can access the internet with someone else's computer or iPad, you can find your email with the information. Still, I don't see much use in having the serial number except to report it stolen, but perhaps with a police report number, your homeowner's or renter's insurance might pay.
But you may want to activate Find My Mac, if you actually hope to get it back, or at least disable it from being used by the thief.
OS X Yosemite: Use Find My Mac instructions
https://support.apple.com/kb/PH18991?locale=en_US
EDIT: Yikes, I see you made another post where you say that in fact, your MBP WAS ALREADY STOLEN. Bummer.
macjack
wrote a reply to you here that may help: How to get ID code of a MAC if it was stolen
P.S. In future, you may want to post in the appropriate forum; your two are showing up in Mountain Lion discussions.