I took Plan B a week ago, and have had no bleeding like I have previous times. This is also my first time on birth control. I've been on it for 4 months but recently changed , and when I had sex I was on the 11th day of the new pills. (I have never missed a pill, even before, and always take them between 7-9 am)

I am a worrier and worry that if I don't bleed this time will it mean I'm pregnant? Please help...