any advice??

ok so i have pcos, so my cycles are very irregular, always have been. but ive used this app for 3 months and it never fails i start and end my cycle when it says I'm supposed to. im 3 days late. i have pains in my abdominal area but nothing like cramps and plus i never cramp (its more like it is really tight pressure), i have to pee constantly and i feel tired all the time. its this signs of pregnancy? Or is it my pcos being weird any advice would be grateful!!