Could tissue be leftover from an early miscarriage from a month ago??

S

My doctor called today and left a voicemail to call her back for a referral to a gyno after the follow up scan from my miscarriage last month The follow up scan was 4 weeks later. I have to call the office tomorrow for actual results so now I'm wondering is this related to the miscarriage or is it something else. The baby never grew hcg was super low 63 at the highest, it couldn't be seen at 5 weeks so I dont think its left over tissue?? Is that possible?? I have had no symptoms I even had a period since the miscarriage.