Tests after miscarriage

Hi there I was wanting some advice in tests after a miscarriage.
I miscarried 2wks ago and I had a scan yesterday for a follow up and it looks like everything has passed. I seen the doctor afterwards to sign some forms for surgery to have a 6cm cyst removed and she gave me a firm for blood tests she said she wanted to check my hcg had gone down and I said that's fine even tho I could just do a pt and see if it comes up negative but she still wanted them done anyway I was looking at the form and she has ordered a test for ca125 I have no idea why she wants this and I can not read her name on the form to ring up and ask her what it is and is it important I do it. Anyone else know what it could for and is it needed done now or is it something I can put off