Period Late

I'm late 12 days today and I'm not sexually active whatsoever. My last two cycles were 4 days early. And I'm "ovulating" like crazy. Super clear and stretchy. I cramp here and there. And somedays I'll be bloated and then the next day I'll be flat again. Is there anything I can eat to kickstart my period? Or should I contact my doctor? I've never been this late before.