Hi my period is late more than 3 months and my pregnancy test gives negative results what happened. and i don't have any pregnancy symptoms. ?

Abnormal cycle: Modern urine pregnancy tests sold in drugstores are very accurate when used properly. Most report accuracy as early as the first day after your first missed period. Many things such as weight changes, excessive exercise and stress can affect your cycle. Your gynecologist should be able to evaluate you for conditions that need treatment.