Endometriosis and reproductive cancer run in my family. Will that have a detrimental effect on my reproductive system?

Maybe. That is difficult to predict. Some women with endometriosis have infertility and pelvic pain and other have no problems. Reproductive cancer can for obvious reasons disrupt childbearing but most cancers occur after women typically have children. So in general you should speak to you doctor about your individual risks and understand what you may do to protect yourself.
Genetics. Endometriosis has strong genetics. Ovarian cancer is also linked to endometriosis. No need to get paranoid. Listen to your body and get the proper evaluation as needed by symptoms of pelvic pain and painful menses. Share this history with your gynecologist.