Does plan b make you miss your period?

Plan B: Taking the "morning after pill" can most definitely delay and alter your menstrual cycle. You need to have a pregnancy test-preferably a blood test.

Possibly: Potential side effects w emergency contraception include: menstrual flow changes (spotting, bleeding, early or late period), nausea, vomiting, dizziness, fatigue, headache, breast tenderness & abdominal pain or cramps. Take pregnancy test & notify dr if your period is 7 or > days late.