It sounds like your girlfriend should probably follow up with a family doctor or a Gynocologist.
Is her pain
more in her stomach
/pelvic region or is it more in the vagina area? Does she have abnormal or normal cycles?
There are many different problems, health issue's and infections that can be causing her pain and discomfort. Just to name a few; Endometriosis, infections, thyroid and hormonal problems have all been known to cause these symptoms.