I started my menstrual cycle on time as usual on nov 21 4 days it was a spotting or extra light bright red and one day it was heavy. today i was cramp?

Sounds normal: Your periods occur because of changes in hormones within your system. While a lot of women have a period every month around the same time, there is variation from cycle to cycle. Ie – a period may come on a few days earlier or later and maybe heavier or lighter depending on the endometrium lining. It may come continuously or with intermittent spotting. These are variation of a normal process