RPL blood tests

Hi I'm 33yrs old & recently had my 3rd MC (no live children)  so my Dr has begun investigation starting with taking my blood for various tests, the results came back mainly negative (thyroid,diabetes,anaemia,lft,anticoagulant test,oestrogen,testosterone) my progesterone came back low & she said she was concerned about one of the antibody tests (antinuclear antibody) so she is repeating these 2 tests on cd21, anyone know why these would be repeated please? (Didn't think to ask at time,was all a lot to take in & was poorly with ear infection too!😩 apparantly ive been referred to the gynae dept at our hosp too,all abit nerve wracking really . Thanks for taking the time X