The reason he can't tell if you have it, is because the laparoscopy is the ONLY way to diagnose endo. If you have only had issues since the tubal, I would highly doubt that it's endo. If you have had pain and problems all along, I would do the laparoscopy. I do recommend however, that you only allow an endo or pelvic pain specialist do your surgery. Many women allow an regular OBGYN do their surgery. This is fine for diagnosis only, but if you do have endo, adhesions, ect., many docs cannot remove it. So they close you up and refer you for ANOTHER surgery!
If you have a specialist do the surgery, they can remove what they find in the 1st surgery, and you will avoid a second operation. I highly recommend a doctor that can excise endo. If not, again, you will have more operations. Believe me.....I have had 4 surgeries for endo. The laser operations only helped for a year, so every year I had to have another surgery! I finally got smart and found a specialist and asked for excision surgery. It has been three years since my last surgery, and I still have good pain relief.
Good luck, and let us know what you find out. I agree that you should not be on narcotics long-term. You will develop a physical dependance (after 2 months you probably already have one), which means that you will suffer withdrawal if you stop the pain meds cold turkey. Find a specialist that can diagnose and treat your pain. Every additional abdominal and pelvic surgery will cause more scarring=more pain. Get it done right the FIRST time!