I started my period 4 days early and on the first day i had horrible cramps, but the next day it was really light. is that normal?

Menstrual cycles: It is not common to have your period come early, skip or be delayed when you are young. It is also more likely to happen if you are very athletic, gain or lose weight, using birth control pills, or have an eating disorder. Still, if you are sexually active, you could be pregnant. I would track your cycles to see if it happens often. Wee you provider if you notice that it continues to happen.