late period but used protection, help!

my period is due today but it hasn't came yet. i've had some PMS symptoms like being emotional and tender breasts and pain in my uterus and acne popped up. this is usual for me but normally my period would come the day or two days after those symptoms. i'm stressing that i'm pregnant even though we use condoms plus pulling out for protection every time and i used a plan b like two and a half weeks ago. i know it could be late because of stressing over it but what's the chance of me being preggo? please no negative comments, just worried. thanksss!