how can i find out if there is a mortgage under my name?
The best way in which to locate this information is by searching the official public records in the county which the property resides. These records will be accessable in many counties online either through the Register of Deeds Office or Clerk of Circuit Courts, depending on your state. I.E. Florida official records are maintained and recorded by the Clerk of Circuit Courts, WI=Register of Deeds, MO=Register of Deeds. Your best bet would be to google both offices in the state which the property resides and see which office holds, maintains the official records and records vital documents.
If the records are not accessible online it will require a quick trip to the county courthouse. Either way the records are easily retreivable and pretty easy to find. By query of the official county records you will also be able to locate, liens, encumbrances, property history, and other recorded documents that pertain to your name including the mortgage.
Example:Florida, in most counties you can conduct a 30 year official records search online by query of the official records online. Google "county name"Florida Clerk of Courts. On the Clerk's homepage there is a link to the official records in 64 of the 67 counties in Florida. There is no registration or cost, query the records by name or in many counties by property legal description and there it is, your mortgage or not. This is by far the easiest and completely free way to get this information.
FYI-If the mortgage was recorded prior to say 25 years you will probably not have online access, even if the query is available online, but the county office will definately show you how to access the records. Employees of the Clerk of Courts or Register of Deeds can show you how to access the records but they will not and can not offer legal advice or counsel.