Hi I Am Two Weeks Late With My Period And

Hi I am two weeks late with my period and am 40 years old, the last time I had sex was 26th July and I had a period again on the 11th August, I've taken two pregnancies tests are both are negative. I have tender breasts, bloating...I should note that for the past year and a half my periods have been slightly erratic sometimes coming every three weeks and sometimes 5 weeks, but this is the longest I've gone without it coming.