almost always on my period...

i'm not really sure why i'm writing this but i'm just so tired of this and overly stressed and this is the last thing i need to be dealing with. i went on the birth control pill maybe a year and a half ago. since then, my doctor changed my prescription twice to different pills because it just wasn't working. that lead me up to this past december, when i ditched the pills and started using the nuva ring. i thought at first it was gonna work great- and i knew i had to give it a few months. here i am today getting my period after having maybe 3 days off. it's not supposed to be my period week but i literally have never once been regular. not once- it's infuriating. i'm still a teen and don't know what else to do- and i have already gone so many times to the gyno and just don't want to continue bugging my mom about it and give her any ideas ya know. has anyone had any similar experiences? please let me know.