My dr hasn't said for sure if I have cancer. Can anyone with experience in gynecology tell me what you think?

please? I am 33 years old, have 4 kids, 3 were born vaginally, 1 by c-section. I went to the hospital on Tuesday because I called my PCP and he told me to go to the ER. He said from my symptoms (absolute dibilitating pain, nausea, diarrhea-the pain was around my belly button and below and to the right) that he thought my appendix was bad. So the ER did a CT scan. They said my appendix was fine and although the preliminary report didn't say it he said I had at least 1 large ovarian cyst. He referred me to my GYN. I called on Wednesday and left a message for an appt. On Thursday I took my kids to school and the pain was so bad I could hardly move. I couldn't pick up my 1 yr old. I was crying, bent over in pain. I called the same GYN office back and asked if they could please get me in soon. They talked to the dr and said to come in right then. I went in and he did a pelvic exam. He said that my uterus is enlarged and dense and that he felt a tumor. He said to talk to my husband about it but he wants to do a hysterectomy. He pressed all over (he said on my intestines, bladder etc) and the pain was coming from my uterus. I said right away that I agreed to the surgery because of the pain. He said there is a possibility of ovarian and uterine cancer but he won't know till after surgery and pathology. He is scheduling a ultrasound and then a hysterectomy. Do you think it could be cancer? I am scared...very scared. I am in a ton of pain everyday. I don't want to wait cause the pain is not subsiding. Any suggestions?