Provera and OPK

  I am on day three of provera and I (out of curiousity) tested this morning. I got the strongest positive I have ever seen on one of these strips. I thought it might be off so I did it again this afternoon and it was the same.  I don't normally ovulate on my own so with that and the provera I'm confused by the positive. Does something in the provera cause a false positive? Any thoughts?