Aiyo don't worry lah, dating discrepancy macam ni mmg boleh jadi especially if your last period date wasn't spot on, baby's scan age is more accurate than counting from LMP je, so doctor is right that it's normal! A few of us went through the same thing, and our babies caught up perfectly fine; as long as heartbeat is strong (which yours is, alhamdulillah), that's the most important sign. Vitamin supplements are always good for baby's development, tapi since you mentioned doctor said don't worry, just follow doctor's advice lah and go for your next scan, they'll monitor if baby's growth is on track or if anything needs attention. Take it easy and try not to stress, stress pun tak bagus for baby