My gf has a regular period schedule but this time on the day of her period she started getting cramps and a burning sensation feeling on her lower part of the belly. The burning sensation stopped after a day then the cramps started and now after 4 days she is now feeling heavy cramps but she is spotting and it is somewhat light pink, but then she said it got somewhat darker after the next spotting and right now she is still having cramps. She took a pregnancy test in the morning but it came negative. It has now been five days since her expected period was supposed to start. There have only been cramps since the day of the expected period but with spotting on the fifth day.