Shock, Scared, Angry And Disappointed

My daughter who jusst started the 6th grade in late August had been feeling tired for a few days then over the weekend she had nausea and threw up a couple of times.
I took her the our family doctor this morning and after he checked her and drew some blood he came to the exam room door asking me to step out to the hallway. The first words out of his mouth were “did you know your daughter was pregnant?” My first reaction was to tell him there must be a mistake because she hadn’t stated menstruating yet.
He quickly suggested I go back in the room and talk to her to see if there was anything she hadn’t told me.
I was shaking as I began asking her if there was anything she wanted to tell me but she looked puzzled so I bluntly told her the doctor thought she was pregnant. Then she said the same thing I did that she didn’t have periods yet.I then asked her if she’d done anything I should know about and she started crying.
She told me while visiting my brother and his wife in early August her older cousin had talked her into having sex while they were playing in the barn. He asked her if she had gotten her period yet and when she told him no he told her she couldn’t “have babies yet” so she let him have unprotected sex with her.
I immediately had so much anger towards him I would have killed him if he had been anywhere close that I could have gotten to him.
As soon as we were finished talking I went back out telling the doctor what she’d told me. He said she was between 7 and 8 weeks along so we needed to discuss things with everyone involved as to what route we wanted to take due to her age.
Her father and I are divorced so this isn’t going to set well with him. She is scared to death about being pregnant and I know my brother and his wife will be very upset and disappointed also.