I missed one pill during week 1due to it falling down the sink drain I continued taking my pills on a regular basis I then missed another pill during week 2 this time thou I took the missed pill and the pill I was supposed to take the following day and have continued to take the pills as directed at the same time every day. I have been on birth control pills consistently for the past eight years. My question... did this increase my chances of becoming pregnant? And how much does stress play a factor in irregular or missed periods?