So I always get my period on a Tuesday but I recently had unprotected sex on Sunday the 7th and took a plan b that night. Was suppose to get my period on the 9th but didn't and here I am on saturday the 13th and still no period. I am on birth control. I'm just wondering if the plan b upset my cycle and if I won't get it until the next month when I'm supposed to get my period. Since I am on birth control.