What Birth Control Should I Be Put On ?

I'm 15. I Have Had Ovarian Cyst Which Interfere With My Period At Times. I Am Waiting For My Ultrasound Results To See If They Have Grown. I'm Supposed To Be Put On Birth Control Because I'm Very Irregular. I Skip 2 Or 3 Months And When I Get It, It Stays For A Week. I've Had My Period Since I Was 12. Which Birth Control Might They Put Me On ? And What Are The Side Effects Of The Birth Control ?