Hi Lisa, welcome... Below is the World Health Organizations definition for t-scores. If you have your DXA print out you can also find this at the bottom of the page on your report.
Normal bone: Any score above -1.0
Osteopenia: Any score between -1.0 and -2.5
Osteoporosis: Any score below -2.5
Osteopenia is not a disease, like osteoporosis, and it means you have some bone loss for your age.
Good luck to you and I hope your osteopenia doesn't get any worse. With proper exercise (weight bearing) calcium (1200 mgs for over 50, and 1,000 for under 50) and vitamin D3 ( 800-1,000 IUs) a day should help you a lot. Some feel the amount of D listed is low so discuss this with your Dr. to see if he or she wants you to increase it.