During menstruation, the genital mucous membrane is more likely to contract germs, it is thus necessary to:
change pantyliners, sanitary pads or tampons as often as necessary
wash carefully after every change, with mild soap and tepid water, moving from the front to the back to avoid contamination
avoid sexual intercourse during periods which help contamination of higher parts of the genital system

What are the 3 rules of menstrual hygiene ?