Hi I'm Just A Little Confused As My Periods Have

Hi I'm just a little confused as my periods have been regular since coming off the pill.This month I was 2 weeks late and a few pregnancy symptoms so was feeling hopeful.Then yesterday I started to bleed and it feels like my period has arrived.It is alot lighter than normal and the blood seems darker in colour. I just don't understand why I am so late this time.Are my chances of being pregnant 0 now?