I use heating pa to tds, alternate between heating pads and ice, it all depends on where the pain is...when I had bad menstrual cramps, I used heat and not baths..you also have to rest...

If you mean menstrual pain then yes.
Magnesium Citrate can help
Maybe 300mg per day ( be aware it can cause diaorrhoea )
Magnesium is a muscle relaxant
It also works with B6 so together they are very very good for PMT and
FIBROMYALGIA so there's a bonus😊
Take Vitamin B50 complex and Magnesium citrate together in the morning.
I find B50 at night can cause nightmares and it is difficult enough to sleep anyway😒
Also be aware that Vitamin B2 contains a compound that makes urine very yellow. It is nothing to be concerned about.
You should also look closely at your diet
Magnesium is abundant in dark green leafy vegetables
I notice in your profile that you enjoy a bourbon and coke.
Nothing wrong with that but alcohol ( and Coffee) inhibit the absorption of Vitamin B6 which is crucial if you have PMT as well.

There can be other reasons for menstrual cramp but try this first because it is helpful for the Fibromyalgia as well as muscle spasm
If you don't get a result you need to be looking at further investigations

Have you been checked for endometriosis? It causes severe pain and cramps and bleeding. I was put on continuous birth control pills and then depo provera shots to stop my cycle. I had a hysterectomy at 35 from it. Talk to your doctor about it. I hope you find some relief. I understand the pain. It is horrible. Hugs

I always dealt with very bad cramping and heavy menstrual pains even back in high school in the 70s when fibro was never diagnosed. It was so hard dealing with the pain and missing out on a lot of things my friends were doing. Hot baths, still to this day! Epsom salts help and I found a new bubble bath at Walmart that has arnacare right in it.

I feel ya!!! Even after quite of few years of not having a period, I can remember the pain...curled up in a ball😟. Tried a lot of the suggestions here...magnesium is great(look for magnesium oil too) but also helped was Evening Primrose. Take all month, seemed to calm things down a bit. Kinda like fish oil helps arthritis. Worse part was Dr. thinking I was over selling how much pain I was in....when they finally gave me muscle relaxers...they didn't do much...oh well 😉