What Are The Chances Of Pregnancy If The Inactive Birth Control Pills Are Skipped?

I have been taking birth control pills for a long time. I chose to start a new pack instead of taking the inactive pills when I finished my last pack therefore preventing me from having menses last month. Does my fertility increase or decrease when I do this. I started spotting last week and was supposed to start my period this week (today) but have not started yet. Should I be concerned that I might be pregnant?