Late Period

My period was irregular often but it started normalcy... Would come on around the 8th then went to tge 11th or 12th.. I had unprotected sex October18th 2 days after it went off... Now my period has yet to come on at all. The last time it did this was yearss ago and never have since then.. I assumed it was stress which it could me... But there have been so many times ive been stressed abd ut never did not come on... Its a week and a half late... I had no symptoms probably light cramping or little feelings in my stomach but nothing too much... At one point i was feeling very tired some weeks ago.. I took a test last week and it was negative... Was it too early? Or is this normal ... As far as i noticed .. No pregnancy symptoms