Is the oral contraceptive yaz dangerous?

I have been taking yaz now for 2 years and 4 months. I started it when I was 14 and now I am 16. My doctor prescribed it to me for pmdd (extreme pms) and acne. So far I have experienced only good things from yaz. My periods are regulated and my face is cleared. When she prescribed it to me, she said that there were NO risks only benefits, including preventing ovarian cancer. I have now been reading the booklet that comes with the prescription and looking it up online only to find that it can cause blood clots, cancer, gallbladder problems, etc! It says on the prescription information that you should only take yaz for pmdd or acne IF you must take it for birth control purposes. I am upset that my doctor did not tell me this and scared about these side effects. I do not want to go off of yaz but if it is risky then maybe I should. My twin sister has been taking yaz as long as I have and she had to get her gallbladder taken out in December. Is it just not worth taking this drug?