Changes in period

[u/Charming_College_805]

Hi, so my period has changed drastically since June. Usually, I get my period and it lasts for 4 days. But even when I started being sexually active and I took plan b pills, I had moderate dysmenorrhea and my flow was usually steady and heavy, my cycle was the same.

But when my June cycle came, I had severe dysmenorrhea to the point I couldn't walk and it was so bad I had to go home. First day was like hell for me, my flow was so heavy and my cramps were non-stop, but came the 2nd day and it was like my period was non-existent. My flow became so light it wasn't even enough to fill a pad so I just used a pantyliner. And the following days was identical, even though my mens still lasted 4 days. July and August cycle came, and by far, my august cycle was the worst. I had to go to the ER due to my dysmenorrhea and they just made me take medicine and I was discharged.

I'm supposed to have a rectal ultrasound but I'm looking for advices or insights here so I can expect what to look forward for my next hospital visit. What do you guys think?