Hello, Thanks for writing to us. Condom has high failure rate around 15-27% and it totally depends on involvement of sex during your fertile or ovulation day. Here, I suggest you to undergo one home pregnancy test at the earliest to confirm pregnancy. Beside pregnancy, reasons of late period and above clinical features could be hormonal imbalance, over weight/ extreme loss, extra mental stress or anxiety, emotional upset, eating disorder, thyroid problem, PCOD etc. On NEGATIVE test, I suggest her to undergo one USG lower abdomen and hormone test to rule out other underlying causative agent and confirm the diagnosis. Kindly, consult with her local gynecologist and take advice accordingly. She may need to take progesterone pill to induce period. You should control body wt, avoid stress, take healthy low carbohydrate diet with avoidance of fatty food and sleep properly. Be well and take care. Practice safe sex always.