im a teenage girl of 17. my periods start being abnormal since starting. and now the case is worsening. my periods started at normal age. but slowly it has been more ireegular and often bleeding between periods. due to backache i was asked to do exercises, can it be cause of it? apart from me my cousin sister also has similar problem. I seeked doctor and was given pills . Im sexually inactive and no other diseases are present. but my height is little short, not much but little.what should I do? can you help me please.??