Well, I don't know for certain that my baby is sticky just yet (but we saw a yolk sac around 5w+5/6d, so that's progress!), but...I have stage 4 endometriosis. This is the second time I've been pregnant, though my first wound up being a blighted ovum.
Pain is purely individual. I have a severe case of it and barely any pain to speak of. I only got diagnosed about 10 years ago because I had a large cyst that had to be removed and that's when they found tissue everywhere.
I started seeing a reproductive endocrinologist and he was not really concerned about the endometriosis. It can cause fertility issues, but it wasn't the end of the line for us. We conceived naturally before he even started us on any fertility treatments.