Growth Ultrasound?

L. • 32 yo, baby #3 due March 2022, 👱‍♂️🤰👧👶🐶🐶

Saw my doctor today (I’m 25 weeks) and she said everything looks normal, baby’s heart rate is where it should be and I measured 26cm fundal height which she said was around where it should be. She went ahead and ordered a 28 week ultrasound for a growth check, any ideas why since this isn’t something she orders for everyone? I’m not high risk, no complications etc.