You need to tell your girl friend not to worry and she has Menorrhagia
, where bleeding is more and heavy. Let her get checked or take tablet norethisterone
5mg tds for 10 days and see how it goes while taking precaution if she is having any other gynaecological condition needs checkup with OBG specialist.
may need further investigations like ultra sound
Scan abdomen and /or MRI and rule out a fibroid or a
PID / UTI/ENDOMETRIOSIS/
REASSURE YOUR GIRLFRIEND NOT TO WORRY.