Period 2 days late on Birth control pill.

Hi guys. I should have started my period 2 days ago on the pill but it does not seem that I will be starting soon and usally I start the same day when i begin that section of the pill. I dont feel pregnant and have not tested yet. Has this happend to someone before and found out you were or were not pregnant. I just need to get some stats on what the odds are. Thank in advance. Im on the Nordette 28 days. I have a one year old boy 🙂