Confused?

I was due on my period on the 23rd Oct, so I'm now 3 days late. I started spotting on the 22nd which lasted 2/3 days and then completely stopped. I've done 2 pregnancy tests, both were negative but I still haven't come on. I'm normally very regular and I've never been this late before? I have no symptoms for AF or pregnancy symptoms. I didn't bother tracking anything this month as I got fed up with the disappointed so I have no idea when I ovulated. Should I ring the doctors? Surely if I was pregnant I would have a positive by now?