@sor1959 You probably know this but I'm going to write this anyway. Every "case" is different and every person is different. I suggest you stay away from online information and the "rabbit hole" because unless you are reading published research or information from valid and reliable sources such as Mayo Clinic or Cleveland Clinic the information you have found may not be reliable. I can't say whether pelvic pain is more associated with later stages as I had pelvic pain too and after my hysterectomy I was Stage 1a. This meant I was diagnosed and treated at an early stage and there was no cancer outside of the uterus lining (the endometrium).

My surgeon told me the following. My endometrial cancer would not be "staged" until after the hysterectomy. The tissue was sent to the pathology lab where pathologists (medical doctors) view the tissue under a microscope and then assign a stage.

You might be referring to FIGO Grade 1 which is a different type of designation. FIGO stands for International Federation of Gynecology and Obstetrics.

FIGO classifies what the cells of the uterus look like. Here is a good website from the Canadian Cancer Society that explains in detail what is meant by FIGO Grade.

Grading Uterine Cancer:

-- https://cancer.ca/en/cancer-information/cancer-types/uterine/grading

Here is more information on Staging from the American Cancer Society:

American Cancer Society: Endometrial Cancer Stages:
-- https://www.cancer.org/cancer/types/endometrial-cancer/detection-diagnosis-staging/staging.html

Do you think that the doctor told you FIGO Grade 1?