Hello. a friend of mine has not got her period since october and has taken two pregnancy test recently which both showed up negative. do you know whats going on?

Some thoughts...: In a woman with regular periods, some causes of a late period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (like birth control pills), hormonal imbalances, etc… Seeing a doctor is a good idea if symptoms are persistent, recurring, or worrisome. Urine pregnancy tests are very accurate by 3 weeks after sex.