How can you tell in a girl is on her p Are their sine Or you can't tell if she is
Unless you really know the person well, you can't tell.
Some girls get mood swings, have weight gain and get a certain "irony smell" when they are on there periods and others have no symptoms, so there is no sure way of determining when a girl is on her period.
she mite be moody,like happy one day sad the next,mad the next day or she mite be xtra hungry,or say things like im blowded or be like my stomach is cramping or hurting