In the case of the B (or center) pillar on four-door sedans, the pillar is typically a closed steel structure welded at the bottom to the car's rocker panel and floorpan, as well as on the top to the roof rail or panel.
On an average a period lasts between 3 to 5 days. It is normal for a girl to have irregular periods in the beginning. During this time, the duration of her periods may vary from as short as 2 days to as long as 7 days. It can take up to a year for periods to become regular.
How Can a Menstrual Period End Early? In most women, the menstrual cycle normally lasts anywhere from 21 to 45 days, but in some women, this is not the case. Several things can go wrong within the menstrual cycle to change the length of menstrual flow and cycle frequency.