• Can you be more specific about your symptoms and what the investigations (e.g scans) you had, have found so far? If your pain is severe, it might be an underlying condition like fibroids or ovarian cysts or also endometriosis.
• Are you symptoms just on your period or elsewhere during the month? Is the pain worse on or off period?
• What symptoms do you you have off your period/in general?
I recommend going to your GP ask for a pelvic ultrasound, and a transvaginal one to see what they find. If you had a transvaginal and/or pelvic ultrasound normally it can pick up adenomyosis.
Its worth looking into the mirena coil can be amazing with heavy bleeding and pain. The mirena works by making the uterus lining thinner, less bleeding and less cramps and pain.
Ask your GP for mefenamic acid and/or naproxen (NSAIDs which help a lot as they are anti-inflammatories and give pain relief). You can also try 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.
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. It's possible there is no cause which is a larger majority of people with Primarh dysmenorrhea but it's still worth trying meds to help with symptoms, a variety of things help and if something helps with symtpoms and your life then definitely stick with it.
Then if ultrasounds pick up on anything (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 excise the endometriosis tissue if they find it (this is a main treatment, but as endometriosis is a chronic illness it very often does grow back, so it's not a one time sort of surgery for many people but it depends on your symptoms, where it is etc).
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.
The stages of endometriosis are actually about how it impact your fertility - so a higher stage more impact on fertility but not pain. So a person with stage 1 endo could be disabled by it and have severe complications but a person with stage 4 may not.
But you could have be adenomyosis where the lining of the womb (endometrium) grows into the muscle of it (myometrium), but unlike endo is localised to the uterus only. Some people do have both but they can only have one, they are different but both very painful.
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
Mangagement can look like pain medication depending on how severe your pain and symptoms are: (can be opioids, NSAIDs) and contraception and hormonal treatments (contraception, 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/