Third trimester ultrasounds

At my 20 week scan, my baby was measuring small and I had a low lying placenta. It wasn’t fully covering my cervix, but it was 1.5cm away and they said it should have been over 2. Wound up following up with a specialist about baby’s growth and he’s fine and caught up, but I’m wondering when they’ll check my placenta position again? My ultrasound tech said they’d have me come in again for one but they haven’t mentioned it since. I have an appointment on Monday and plan to bring it up, but just curious.