Elevated IgM. TTC

Karina
Hello, I had a miscarriage back in December 9 weeks. A chemical preg last month. I went to OB to get antibidy testing and everything was back normal except IgM. Said my level was 48 and normal is below 25. OB states to make an early appt when I get my BFP to be started on baby aspirin or heparin. Anybody heard about this or had this done before?