If you've had shingles in the past is it possible you will ever be tested positive for genital herpes ?

It really depends on the test. I didn't know this, but after a little research I found out that both the shingles virus and genital herpes belong to the same virus family. If you use a certain test then you could generate a false positive. A specific test should be used to differentiate the two viruses. Why are you asking this?

I had shingles years ago and now they tested a culture and say I'm positive for type2 herpes.

Has your partner been tested?

I would honestly go and get retested with a test specific for genital herpes. The shingles could be giving you a false positive.