today is cycle day 36 with no signs of my period in sight. my cycle is consistently between 27-31 days long (so i'm 5-9 days late). i have never been late in the 11 years i've been menstruating. also, i track my period meticulously. i am not on hormonal birth control and would totally be a-okay with being pregnant. i took tests on days 32,33,34 and today (36), and they have all come up negative.
what is causing me to be late? also, i dont take any meds and i am very laid back and rarely get stressed.