Next Step-HSG Test

I'm scheduled to go next Tuesday for a hysterosalpingogram. This test will determine if I can conceive on my own. I would have gone for this test last January when I had a laparoscopic surgery to remove a "so called cyst".  The surgery came to a hault  when my doctor discovered I had Stage 4 Endometriosis. Many doctors have told me that I need IVF but I really want to find out for sure. I'm guessing that I will need IVF and a little worried to find out any other news. I'm trying to stay positive but also want to be prepared for the worst.