Hindi yan unusual ha, some of us had BPS (biophysical profile) done earlier din depending sa OB preference or if may concern sila sa pregnancy, pero best talaga na tanungin mo directly ang doctor mo kung bakit 22 weeks pa lang, baka may specific reason or it's just their protocol. Wala namang harmful sa ultrasound so relax ka lang, pero definitely ask your OB to explain kung gusto mo ng peace of mind!