new on birth control HELP

so i’m seven team and I just started birth-control without my mom knowing. I went to the doctor made an appointment and then got my prescription no problem. My doctor had told me that I can take the pill whenever as long as I know I’m not pregnant so I took it about three days before my period was supposed to start. Since I started my period hasn’t stopped it’s been going for about a month not spotting a lot of blood. Is this normal?? I feel like it could be because I started at the wrong time, my sheet of paper with information that came with the birth control had said to start on the Sunday after your period but I had went from what my doctor had said and just took it whenever. i’m getting concerned, pls help!!