So last month I took plan B, then got my period days later. Then I had unprotected sex again (withdrawal method) Jan 1st, I was supposed to start my new cycle last week around the 21st but It hasn't even started yet and no symptoms. I felt irritated by everything last week which I thought was PMS but it seems like I'm not going to have a period this month. Has anyone else had this? Should I be worried or take a pregnancy test? Also Jan 1st was my 1st day of my fertile window.