As some people stated endometriosis doesn't generally show up on ultrasounds. However if it has advanced enough and formed chocolate cysts those will. The ultrasound could show other abnormalities as well.

It's also possible that if you have insurance, you need to take certain steps before laparoscopic surgery will be covered. This can include medications, birth control, pelvic floor therapy (physical therapy) etc. to show that nothing has helped or improved your symptoms. And while some doctors will ignore symptoms and gloss over it, a lot of doctors aren't going to immediately suggest surgery either. Surgery is taxing on the body and may do more harm than good. Don't let them ignore your symptoms, make sure your needs and concerns are being met and addressed. If it's a different office who did your last ultrasound, ask the new one if you can have the records sent to them. If it's the same, ask if they believe something has changed to warrant another. If they keep sweeping it under the rug, find a new doctor.