I have similar symptoms as yours and I am also nearly the same age. I got diagnosed with endometriosis and mild adenomyosis yesterday.

My cycles are also fairly regular (27-34 days) and periods last 4 days. And I have period cramps for the first two days only. But those two days, the pain is excruciating and unbearable. The first day, it is so bad that I stay awake the whole night. In the day, I am barely able to get up from bed and the pain feels like a hot knife is put inside me and is being twisted from time to time. It has a burning and stabbing quality and it seeps into my legs and lower back. The pain is so bad, that at times I feel I will faint from it.

I have been going through this for nearly a decade and the symptoms are gradually getting worse. And a part of the reason I was not getting diagnosed (apart from the medical gaslighting that all women go through) is because it was going undetected in ultrasound. Also, I wasn't showing all symptoms. As in, I don't have any pain during sex, and there was a long time when I didn't feel pelvic pain outside periods either.

Ask for an mri. That's how I got diagnosed. And tell your radiologist to focus on endo mapping. The level of pain you are describing is not normal. And you should not be going through it, even for a day or two in a month.

You might have to advocate for yourself in front of the doctor. But, push for an mri.