3 consecutive mcs

Ta
So I'm going through my 3rd consecutive miscarriage. The Doc seems to think it's ok to just keep trying. At what point do we go and see a fertility doctor?? This month was my first month on clomid, I was so hopeful. My period was 4 days late, I never got my pos preg test and now I'm having a very heavy and abnormal period. When do we go see a fertility specialist?