Question....?

I'm 3 days late. I took a test Monday night, it came back negative. I believe I ovulated sometime last Mon-Wed. Could ovulating late be what's delaying my period? I'm on CD33 right now, & for the past 3 months my cycles have been 30-33 days long. I know I won't be starting AF today because my temp was 98.3. My temp has been elevated since last Wednesday. My biggest question, is why the negative tests when I'm late? On Monday I thought I had started because of the cramps I had, but nothing happened. Ever since then I've had hardly any "cramps" but they appear every now & then. The "cramps" are normally only on my left side or my right. Never in the same place.