Hello well first I need to know if there is any history of unprotected intercourse which might be the most common reason if yes please get  upt done... if no then definitely you need to meet a gynecologist and yourself evaluated for any hormonal conditions like thyroid  or PC OS you also need to get ultrasound abdomen and pelvis done thank you

Hello, Is she sexually active? If yes then ask her to do a urine pregnancy test. If the result is negative, there is no chance of pregnancy. if the result is positive, visit a gynaecologist for furhter evaluation and management. Also, if she is not sexually active, ask your friend to consult a gynaecologist. She will examine her to rule out the cause behind missed periods.

Hello. In case she is sexually active, a urine pregnancy test needs to be done. If it's negative, do an ultrasound. Depending on investigations, further treatment will be given