Another BFN

Hi. I’m 36 years old with a four year old son. My son is special needs and has Autism. He tests me everyday but in the same breath, I love that kid with my whole heart. We decided to try for another child after some difficulties in our marriage over the last couple of years. My period is late and I still have a negative. I already feel like my body is failing me with all the ovarian cysts, pelvic pain and prolapse. I feel defeated.