Taking birth control pill with IUD?

I was diagnosed with endo 15 years ago and was on the pill for a while and then switched to an IUD 10 years ago. Im on my second IUD but just had an ultrasound done which showed two chocolate ovarian cysts and fibroid tumors. I also have adenoysis (spelling wrong) and my uterus is out of position because of the adeno. Ive been having increasing pelvic pain and leg numbness as well. My gyno has suggested starting a birth control pill while keeping the IUD as well. Has anyone gone this route before? Is it effective? Im confused on how additional estrogen from a BCP would help. Should I push for excision?