@miserablee I sympathsise, maybe if your pain is severe it might be an underlying condition. It could be fibroids or ovarian cysts.
I recommend going to your GP ask for a pelvic ultrasound, a transabdominal ultrasound and a transvaginal one to see what they find.
Are you symptoms just on your period or elsewhere during the month? (Because if its just on your period, unlikely to be endometriosis).
Also what symptoms do you say you have? What symptoms do toy gave during your period? And if you have symptoms not on your period - what are they? Is the pain worse on or off period?
If you had a transvaginal and/or pelvic ultrasound normally it can pick up adenomyosis.
I recommend asking the GP to try the pill and/ or mirena coil can be amazing with heavy bleeding and pain. You might try different pills first. Yes, they treat the real cause as well (mirena will may the uterus lining thinner, less bleeding and less cramps), but with the pill, will treat symptoms. So definitely try that, sometimes the progesterone only pill (mini-pill) can be better for some.
Also ask your GP for mefenamic acid and/or naproxen (NSAIDs which help a lot) and tranexamic acid (helps reduce heavy bleeding) - you need to start taking it days before your period starts so that it can work at best capacity. The same with ibuprofen and/or paracetamol. Start taking it 3/4 days before and it will be much better.
You may have 1. Primary dysmenorrhea (heavy bleeding and painful periods with no condition or cause or 2. Secondary dysmenorrhea so a condition e.g endometriosis or adenomyosis causing it. You will need to try NSAIDs and mirena/pill and Tranexamic acid first before any further scans like ultrasound and MRI. Often if the pain is significantly reduced with said treatments its more likely (not 100%) to be primary dysmenorrhea. Also very dependant on whether you only have symptoms on your period or across the month as to whether you have primary or secondary.
Then if ultrasounds pick up on anythibg (pelvic ultrasound or transvaginal) you may need to have an MRI to see endometriosis. However, the only way for definite diagnosis is a laparoscopy and then they will often excise the endometriosis tissue if they find it etc. But endometriosis is a chronic illness and cannot be cured, after surgery it will grow back, it cannot be excised from everywhere to leave organ functioning intact and then post-surgery adhesions often form.
The main symptom of endometriosis 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. Another popular cyst is haemorrhagic ovarian cysts with endometriosis.
But you 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. Thus, symptoms are mainly a couple days before a period and during your period. Main endo symptoms:
• Irregular or heavy periods
• Pelvic pain
• Pelvic pain on opening bowels (dyschesia) and wider gastrointestinal symptoms (diarrhoea amd constipation)
• Pelvic pain on passing urine (dysuria) and bladder symptoms sometimes
• Referred pain to the tops of the legs or back
• Fatigue
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 and symptoms are (can be opioids, NSAIDs) and contraception and hormonal treatments (gonadotrophin releasing hormones).
The links below have much more detailed and useful information.
https://www.leedsth.nhs.uk/patients/resources/endometriosis-2/
https://www.nhs.uk/conditions/adenomyosis/