My health care professional said she suspects that i could have uterine cancer. what kind of test will tell for sure?

Endometrial biopsy: A very small tube is inserted through the cervix until it reaces the uterine lining. A syringe attached to the end pulls back and the lining comes into the syringe. The cell are sent to the pathologist for examination for abnormal cells . The procedure is done in the office.

Uterine Cancer: Uterine cancer is usually found in post menopausal women. Only 5% occur in your age group, often in women who have polycystic ovarian syndrome (pcos), where one has to be concerned with not only uterine disease, but also ovarian tumors. Sometimes an innocent looking polyp can also harbor cancer. The only definitive test is an endometrial biopsy, which you should consider without delay.

Different options: It depends what you mean by "for sure". An endometrial biopsy will miss a small percentage, especially if a polyp is suspected. A hysteroscopy and biopsy (looking directly into the uterus) has more certainty but is more invasive and uncomfortable and will require some anesthesia. I would question why at your age uterine cancer is such a suspicion.