Hello!
You need to investigate into this forum and online resources on TCM. TCM knows a lot about menstruation as well as of other pains which traditional medicine knows nothing about. The idea of our Ancestors on the subject in most of their writings is that neither menstruation nor any other natural process, birth or else, was ever meant to be painful "out of the box" to any part of the body. Pains during natural processes are indication of disease that if left untreated grows worse with age.
Most women with discomfortable menstruation experience more serious problems after 40, such as myoma, which is the result of non-treated blood/phlegm stasis which usually expresses itself in painful menstruation. All over the world medics lie to women that "pains are normal" and related. These very medics have to lie after some 30-40 years that "ok em... myoma is also normal, you can't have your womb going till 90 years goy" etc.
Look:
"Most American women will develop fibroids at some point in their lives. One study found that, by age 50, 70 percent of whites and 80 percent of African Americans had fibroids. "
— https://report.nih.gov/nihfactsheets/viewfactsheet.aspx?csid=50
If you search for the procent of discomfortable menstruation, you will find the same or more numbers. If you read myoma stories you will always find discomfortable menstruation. I have never seen anyone with completely comfortable menstruation who would have any fibroid.
Here is how fibroids emerge - they fully emerge from the same patterns that cause painful menstruation. http://www.itmonline.org/arts/fibroids.htm
Here I collect all information that I learned about the subject so people can find it in one topic:
Any pain origination:
https://love.drdgacupuncture.com/pain-according-to-tcim/
Connection to Liver channel:
https://www.acupuncture-points.org/liver-blood-stasis.html
https://www.acupuncture-points.org/liver-blood-stagnation.html
https://www.acupuncture-points.org/liver-functions.html
https://www.acupuncture-points.org/liver-channel-cold-stagnation.html
https://www.meandqi.com/tcm-education-center/symptoms-list/menstrual_cramps
Connection to hormones:
https://ancient-forums.com/viewtopic.php?f=17&t=241&sid=c58fda660bcac7e8a9ffd5804e363f1c
Lifestyle influence on health including menstruation etc.
https://ancient-forums.com/viewtopic.php?f=17&t=59313&sid=0a3e1ba4f1926ec22c2507aac4a14f56
(All Liver cold stagnation and Spleen Yang deficiency are related to this)
Examples of how some specific problems may be solved:
https://ancient-forums.com/viewtopic.php?f=17&t=43517
https://ancient-forums.com/viewtopic.php?f=17&t=26091
https://ancient-forums.com/viewtopic.php?f=17&t=67041
Remember every case is unique. When you say "pains" no one knows what you mean. There are breast pains, ovary pains, there are intestinal pains that can also come without any other pain during menstruation or in any other part of the cycle (search "IBS menstruation" - it might be connected to Liver Channel Cold stagnation as well), etc. - you have to know what organ is the source of pain exactly.
Usually people would advise to come to see TCM doctor, because TCM has levels of education and experience in it. I had hard time to find the actual source of some my things and had to ask Demon's advise. I still learn and I can say: there is no such thing in nature as what xians put as "god's punishment" etc. They talk about "gods punishment" and "gods will" whenever they fail to find the answer. "If I do not see the way, it means there is no way" attitude. It is the silliest thing to conclude.