CD10 and sonogram???

Hello. I do not post often, but I was hoping someone could help me.

I had 2 miscarriages since having my son. I am under the care of RS of NY. They are doing different tests on me to try to figure out my problem.

I have done a bunch of tests already including bloodwork, CD3 bloodwork and sonogram, CD7 saline sonogram and tomorrow I go for CD10 bloodwork and a sonogram for my follicular something?

Has anyone done this and if you did, what exactly do they do and what do they check for?

Sorry to ask so many questions, but I am curious what they are testing for.

Thanks so much for your help