Most likely a doctor will put you on birth control and yes that will help shorten and lighten your period. Talk to your mom about taking you and let us know how it goes!
Hi, You seem to be having longer than normal periods. I'd suggest visiting a gynecologist to evaluate you, instead of starting any medication on your own, especially birth control, unless you are also sexually active. A doctor will be in the best position to figure out if it's normal or not and prescribe the right medication. All the best!