Other reasons for being late?

Lexi

Hi ladies so this month I am 9 days late for my period. I have been having some pressure and slightly twinges in my pelvis. My periods are always 27-28 days to the dot and I start first thing when I wake up. Even being the most stressed I have been in my life I was only a day late. I took a test a couple days ago and it was negative. What else could it be?