13gemini72 is right, endometriosis can cause very heavy periods and bad cramping. Also,
cysts,
no matter the size can cause pain. It is a wonder how something so small can cause pain, but it can. I'm glad to see that you are going to see your gynecologist. I know 3 weeks seems like forever away (I will have surgery in about 3 weeks), but maybe you could call your pcp and just tell them what your medical record shows and ask them what they think.