Why Am I Having Premenstrual Pain With No Menses?

Hi, I am 38 and 10 days late on my period. I have always been regular. I had a blood test 7 days ago and a negative result. I took another HPT this morning and again negative.
When I was due for my period I was experiencing period pain but stopped after a few days and today I'm having pains again. Do you think this is due to my age, or I just happened to skip last month??