Question

reason behind periods​

Answer 1

Explanation:

menstrual cycle in females with 28 days cycle repeats again

Answer 2

Answer:

egg or ovum from any one of the ovary comes out and say for a day or two in the fallopian tube or the oviduct waiting for the sports to fertilize it. at this time, the lining of the uterus starts building up to give protection to the fertilized ovum. when no sperm comes to fertilize the egg in the fallopian tube, the ovum moves down into the uterus. it stays for a day waiting for the sperm . when no sperm comes, then the lining of the uterus starts breaking and sheds blood. this blood is passed through the vagina with that unfertilized ovum. this is xalled as menstruation or well known as periods