I have been on birth control pills for about 4 years now. This month I went on vacation and forgot my new pack of birth control pills. I would have missed 4 days while I was away and then I completely forgot to take when I got home. I didn't want to play catch up for 5 days so I decided to just not take the pills this month and start them up again next month. My boyfrend and I did have unprotected sex a couple of times in the past week. How long after not taking the pill can you get pregnant?