I had 4 miscarriages and I'm very upset ...

I would like to know: I was pregnant for 10 weeks and my heart was beating normal, the embryo developing normal and I ended up suffering another abortion, this is already the 4 abortion, of the other pregnancies I did not hear my heart beat, I already heard. From the 2nd abortion I did several exams and did not give anything my husband also did and gave nothing. Is that what happened? Did I do two curettages harm to the next pregnancy if I try? Do you have any type of treatment to diagnose the causes of so many abortions? I took the exams at a clinic in Belo Horizonte. Another thing of this abortion I had to do the genetic study of the material harvested in the curettage will the cause of the abortions appear? I'm so upset and wanting an answer to reassure me. This abortion is more difficult to overcome. Oh I have rheumatoid arthritis, does it disrupt pregnancy? Sorry so much question is that my doubts? Thanks.