I am really sorry that your doctor has given you such false information. What it sounds like is that she is not experienced with this disease so I would look for another doctor.
1) If you have a family member with this disease you have an 8 fold chance of having it.
2) If you are in so much pain and also at times vomit that is NOT normal and IS a symptom of Endometriosis.
3) Some people have different part of the insides effected. For example your friend with the miscarriages, sometimes people only have their tubes effected and then there are some that have the pelvic wall, rectovaginal, bowel, bladder, ureters, uterus and/ovaries. No one with Endometriosis have the same symptoms. You could have stage IV disease and not have any pain or you could have Stage I and be disabled and vice versa. This disease does not discriminate and that is why it is hard for doctors to treat and diagnose. Those that take the time out to learn about it with updated information and research will help their patients better.
4) Were you on BCP ever to help control the pain of your periods by chance? Sometimes women will be put on it early in their teen years and stay on it for years and sometimes decades. When they do come off it they are hit with sudden pain out of no where and that is because the BCP has been masking the disease, hence why some women take 8-11 yrs to be diagnosed and later in life.
5) I would recommend getting a second opinion and try to get into see an Endometriosis specialists. If you do have it you want to be with the best of the best to treat the disease..There is no cure for Endometriosis but there is effective gold standard treatment which is excision surgery which cuts the disease from the root. Most OBGYN's only know how to laser and that only gets the surface of the disease. So if you were to have surgery please please make it with an Endo specialist who has the skill to excise the disease.
You know your body. Something is wrong. Most GP's do not take Endometriosis seriously and actually delay the diagnoses process which in turn the patient feels alone, discourage and still suffering.
Please get a second opinion.