What Do Delayed Periods, Bloating, Diarrhea With Dull Pain In Ovary Suggest?

I have irregular periods but generally have one every 28-36 days. I m currently 16 days late, negative pregancy test, bloated , diarrhea couple of times a day the last week, left lower (ovary area) feels like a sharp pain full ache. Never been this late on a period and concerned.