Oh dear, I completely understand why you are worried, especially with what happened in your previous pregnancy, any mother would feel the same way. Since the doctor mentioned baby is measuring a little small, it may be worth asking for a referral to a specialist or a more detailed scan, just for your own peace of mind. Please do follow up closely with your doctor and don't hesitate to voice out your concerns, because your history is something they really need to take into consideration. Sending you lots of love and prayers, take good care of yourself sayang.