I had an unprotected sex on October 20th and had a Plan B (morning after pill) within 12hours. After a week, on October 27th, I started to have a period again (my last period was October 10th). It was pretty heavy and was bleeding for 4days but today (today is the last 4day of my second period) I had an unprotected sex again because I thought I was on period... is it possible for me to be pregnant after all of that?