Hi, my name is Chanel and i've been on my period for about 3 weeks now and i just left the doctor's office. She prescribed premarin to help stop the bleeding but i'm very skeptical about taking it. I looked it up online and the side-effects are very frightening. The last time this happened, I was prescribed vitamin K to stop the bleeding. Can someone please clarify exactly what premarin is and how it is going to stop this bleeding?