Could i be pregnant, and if so should i take a test today?

My last period was on the 21st dec, it lasted 7 days as usual! I had on the 30th dec, 1st 2nd and 3rd of jan! I am due on today but so far no period in sight! Periods run like clockwork and I am usually bleeding first thing int he morning on my due date! I had a slight twinge in my ovary area last nite lasting seconds but nothing else! usually my are sore roughly 4days before my due date, but they have only become sensitive today, with bright blue veins on my an nipple are! could I be pregnant?