My gf late period 2 weeks and now pain like period from 4 days but not happen yet.we active sex 3 days before real period that was safe as i think condom used?

Late period: Reasons for missed / late period include: an anovulatory cycle in which no egg is released, marked v or ^ in weight; eating disorder; Over-exercising (endurance athletics), stress, travel, significant illnesses, oral contraceptives & other meds, Illegal drug use, breast feeding, hormone imbalances and medical problems (i.e., PCOS). Pregnancy is #1 reason. She can take pregnancy test to know .