When I had drug induced lupus [DILE] my ANA was only abnormal once. However, my anti-dsDNA antibodies were very high. The medication you are taking might be know to cause certain antibodies to develop. I was taking Humira and that is what caused mine. This page has a list of the different antibodies that your doctor can test for.
www.lupus.org/answers/entry/lupus-testsAlso make sure he tests your C3 and C4 Complements. The C3 Complement was what my rheumatologist used to monitor the DILE activity since my sed rate was always normal.
Hope you get some answers!