Plan B is a type of emergency
contraception pill. It is birth control pill that can prevent
pregnancy after unprotected sex. It is a one-dose regimen which contains 1.5 milligrams of
levonorgestrel. Depending upon where you are in your cycle, Plan B works in one of these ways:
1. It may prevent or delay ovulation.
2. It may interfere with fertilization of an egg.
Potential side effects of Plan B include: nausea,
abdominal pain, fatigue, headache, menstrual changes (unexpected bleeding),
dizziness, breast tenderness and vomiting.
You are experiencing some of the above mentioned effects.
But, nothing to worry. The symptoms will slowly come down. Since it is a hormone preparation, your periods will be back to normal in next cycle or two.
It is advisable to have protected sex than to consume the pill regularly as Plan B is to be used as 'emergency' contraception.