Confused, Any tips?

I have Endometriosis and Uterin Polyps. I go in for vaginal surgery to remove the polyps and any endometrial lesions that may be on the inside of my lady parts then having the Kyleena IUD placed. It's the same as Mirena just smaller and less of a dose. My periods have always been brutally heavy and painful, do you think my periods will become lighter or completely stop with the IUD. Also can I use the menstrual cup with an IUD. I have heard so much about it that I want to try it