My period is been longer than usual just like last month and i don't know why it's never happened before till last month and this month?

Hormones: Longer periods often have to do with hormone imbalance, thyroid problems or sometimes weight issues (thin/heavy). An abnormal period is one that lasts for > 7 days, or with bleeding more than once per cycle, or if super heavy and you are changing pad in 1-2 hours or less. If any of these are case, consider seeing gynecologist for evaluation. Birth control pills can help regulate your cycle.