Don't worry, it's never Lupus. -Dr. Gregory House.
But seriously, a simple ANA titer should give you an idea of how active your immune system is. It won't diagnose Lupus, but it will tell you when your immune system has kicked into overdrive, whatever the reason. It's a lot less of a hassle than getting tested for Lupus yearly, so consider doing that instead. Should the ANA ever go through the roof, then you can test for Lupus.