What Causes Heavy Bleeding And Pain With A Red Colour Clumpy Discharge?

My girlfriend is freaking out today. She is on her period for 3 days now. The period she describe is more painful then before and it came a bit late like a week. Anyway, today in class she went to the bathroom with great pain and notice something in her stomache came out to be the size of a peach and it color are redish-brown. What can this be Dr.?