why do girls experience period?

Question: why do girls experience period?
- Keywords:
  menstruation period
Asked by cute ascar to Sammy, Marta on 13 Jul 2017. This question was also asked by KIM, Nish, Eliano.
- Sammy Wambua answered on 13 Jul 2017:
  
  Hi cute ascar,
  
  Thanks for such an interesting question. I read your question and almost said uuuuui… then I realised I will not have answered you this way.
  
  OK, having periods is the body’s way of preparing for pregnancy. Once one gets their period, it means that they are physically able to become pregnant and have a baby – although they may not necessarily feel ready!
  
  Periods happen as a result of hormones released from a gland at the base of the brain called the pituitary gland. These hormones cause an egg to be released. At the same time, the lining of the uterus (or womb) is becoming thicker – like a soft and spongy bed, ready for the egg.
  
  As a man, I can’t start imagining what a bother they are but, if it is any solace, periods are nature’s way of saying you are normal even fertile.
  
  I hope this helps.

Question: why do girls experience period?