My daughter has been complaining about a lump in her lower stomach and pain for years. Doctors can't seem to figure out what is wrong with her, although I don't think they ever did any serious testing since she was only 16 when the symptoms started and had not at that time ever had sex.
She faints a lot, especially when the weather is hot and has dizzy spells.
She is now 19 and told me today her period blood is copper orange.
Can you give me a clue what to tell the doctors to test for?

Go to her doctor right away. This is the same thing that happened to BOTH my sisters (one blood sister, one inlaw) and one has endometriosis, the other has poly cistic ovarian syndrom.

Good luck hon.
Don't let the doctors just shrug you off. DEMAND on the tests. Ultrasounds, blood tests, and a pap smear and pelvic exam.