If you enjoy your on your length for longer than 2-3weeks?
And its other been like this ever since i started what does that parsimonious?
Answers: It just means your hormones are imbalanced and your body think that its normal to have it this long but really its not. I penny-pinching its completely normal to have an disparity, but to have your period that long is inconvenient and annoying.
I would suggest going to see your doctor and cooperate to him/her about it. They will most likely put you on birth control which will regulate your hormones and you will bring back a normal period that will ultimate 3-6 days at the most! :)
hope this helped!