What are Periods? Why this happens to Girls?

A cycle is counted from the first day of 1 period to the first day of the next period. The average menstrual cycle is 28 days long. Cycles can range anywhere from 21 to 35 days in adults and from 21 to 45 days in young teens. The rise and fall of levels of hormones during the month control the menstrual cycle

Once you get your period, you'll need to use something to soak up the menstrual blood. Your choices are a pad or a tampon. If you've ever seen them on the store shelves, you know there are many varieties to choose from. How do you know which one is right for you?

Pads are rectangles of absorbent material that you stick to the inside of your underwear. Some have extra material on the sides (called "wings") that fold over the edges of your underwear to better hold the pad in place and prevent leakage. Sometimes, pads are called sanitary pads or sanitary napkins.

Tampons (say: TAM-ponz) also absorb menstrual blood, but they work from inside the vagina. A tampon is also made of absorbent material, but it's pressed tight into a small cylinder shape. The question all girls wonder is — how do you put them in? Some tampons have applicators, which are plastic or cardboard tubes that help put the tampon in place. Other tampons can be inserted using your fingers.