HT1937: iPhone: Wireless carrier support and featuresLearn about iPhone: Wireless carrier support and features
Unfortunately there is no way to track the iPhone if Find My was not activated in iCloud.
Note it is not a good idea to publish personal information on a public forum as we are not Apple but fellow users.
You can't trace your iPhone by IMEI number.
If you had "Find My iPhone" enabled then you may be able to locate it. If not, you cannot locate it. If it was enabled then you can try locating it via http://icloud.com on a computer or the App "Find My iPhone" on another iDevice. Note: this will only work if your device is connected to a network and the device hasn't already been restored as new and/or "Find My iPhone" has not been disabled on it.
If you think that your device was stolen rather than lost then you should report it to the police. In either case you should contact your carrier, change your iTunes account password, your email account passwords, and any passwords that you'd stored on websites/emails/notes etc.