Hepatitis b blood test shows both anti-hbs (i was vaccinated 13 years ago) and hbsag. does that mean i was recently exposed or that i am chronic?

Needs investigation: Were you tested for hep b before you got vaccinated? What are results of rest of the tests for hep b markers? Is it possible that you were already infected when you got the vaccine? Persistence of hep b s ag generally means chronic infection. See this site for more info about hep b. http://www.cdc.gov/hepatitis/hbv/hbvfaq.htm.

The latter: It is likely, if the test results are confirmed, that you were a chronic carrier of HBV before you were vaccinated. Some people have both HBsAG and antihbs and behave as other chronic carriers.