late second period after plan B

Please help. I am exactly a week late for my period. I took plan B last month and had my period delayed by two weeks, but I got it and it was as any other period I've had before. I haven't had sex since then but now a week late. I don't have any symptoms (both PMS or pregnancy) ; no soreness of breasts, no cramping. Is this still plan B messing with my cycle? I am absolutely terrified because I've read stories of women who bled every month like an actual period and still ended up pregnant. Please help me