The females all over the world bleed every month as soon as they hit puberty stage. This is a normal condition that all females should undergo in their point of life as they finally reach the age and their bodies are ready.
This takes place every month and completes a cycle of twenty eight days.
Biologically the walls of the uterus are the once that shed out during this period and at times can be painful.
This only happens to a small number of women who are said to be experiencing cramp pains during this period.
Ladies are always to maintain high hygiene during this period.