I have so many questions

This past 5 months I had a miscarriage and I had one a year before this one. I miscarried so late in the pregnancy the doctors don’t even know why I lost the baby. Could me bring rh negative has something to do with me losing the baby. I do want to try again but I’m scared of the same result each time. I was 2 days from being 14 weeks when I miscarried.