What are all your symptoms? Bleeding and pain where? Also if it is localised to your periods only then it may not be endo. Endometriosis is where endometrium like tissue (but not endometrium tissue), grows outside the womb, most commonly in the pelvis, bowels or bladder or the top of the vagina. Ocassionally it can be elsewhere in the body.
The main symptom is not actually period pain because endo is not a period condition - it's a whole body inflammatory condition where the endometriosis tissue even produces its own oestrogen and the pain is felt throughout the month not just when on your period. Often endometriosis on the ovaries can form cysts containing old blood called endometriomas (also known as chocolate cysts) which can be very painful. So this is a massive sign that you do have endo.
Some of your symptoms could also be adenomyosis where the lining of the womb grows into the muscle of it, but unlike endo is localised to the uterus only. So to distinguish what it could be, you'll likely have an MRI. But crucially you can still have endo even if they don't see it on the scan, the only clear way for diagnosis is a diagnostic laparoscopy and then mangagement can look like pain medication depending on how severe your pain is (can be opioids, NSAIDs) and contraception and hormonal treatments (gonadotrophin releasing hormones).
Main endo symptoms:
• Irregular or heavy periods
• Pelvic pain
• Pelvic pain on opening bowels (dyschesia)
• Pelvic pain on passing urine (dysuria)
• Referred pain to the tops of the legs or back
• Fatigue
The links below have much more detailed and useful information as does the Endometriosis Uk website. Hope this helps.
https://www.leedsth.nhs.uk/patients/resources/endometriosis-2/
https://endometriosis.cymru/diagnosis-treatment-and-care/diagnosis-pathway/
https://www.nhs.uk/conditions/adenomyosis/