Antibodies in blood?

I’m 5-6 weeks pregnant. This is my fourth pregnancy, two babies and one miscarriage. I have O- blood type.

I had a MC at the end of June. Got my rhogam shot in the ER. Found out I was pregnant again August 7. I did not have a cycle between the MC and positive test.

My bloodwork came back positive for antibodies, obviously because I had the shot and it’s still in my system. But my midwife wants me to get a scan with a perinatal specialist. I can’t get much more information out of them except that it’s because there were antibodies present.

Has anyone been through this? Would the antibodies cause any harm? It’s not like we don’t already get the shot while pregnant... I’m just so confused as to why this is a big deal. Any insights?