I interned with Saral Designs Pvt. Ltd. on facilitating the segregation and disposal of menstrual sanitary waste. They manufacture machines that manufacture sanitary pads. More about them later. In the female body, ovulation, i.e., the release of the egg, happens once every 28 days. To prepare for a possible pregnancy, the uterus is lined with tissues and blood vessels. If a fertilised egg does not successfully embed onto the uterus’s lining, this lining is shed. This monthly menstrual bleeding is what we call periods.