My period has been starting weeks early

As the title says, I (24f) have been on birth control for almost a year now. My doctor first put me on Yasmin and it did what I wanted it to: shorten my period and make it less painful, but I guess it was discontinued by the FDA for whatever reason. They switched me (without telling me) to Nikki and this is my sixth month on it and holy shit, I am cramping so bad and my period has been consistently 1.5 to 2 weeks early every month. At first I was just thinking that my body had to get used to the hormones, etc. but after six months it's just getting worse. I am planning on going to a doctor to see if I can switch or something but I wanted to come here first to get some recommendations or anything that may help. I know going to the doctor is the best bet, but here I am lol