Is it normal for Plan B to cause an early period even if i’m on birth control? i have 5 pills left in my pack so my period isn’t set to start for a while. I took a plan b early on in my pack because i missed a pill.

Yes a common side effect of plan B is irregular bleeding

Emergency contraception can mess your body up for weeks and sometimes even months, so yes it’s entirely normal to experience irregular bleeding. Irregular bleeding is also a common side effect of the pill itself. You’re no longer “due” or “late” a bleed, it just happens or it doesn’t.