Ultrasounds?

I had an doctor appt and an ultrasound done today, this was the second ultrasound i received...so when i was waiting i seen my friend that i use to work with, and me and her and the same, ,im due on the 21 of july and shes due on july 19...so she was tellin me that she had gotten ultrasound every month, im like uh, this is my second one...we both 33wks and shes still smokin cigarettes...im like omg...and plus she was very bad on drugs...i wonder its cause she as a high pregnancy or what??? im just curious, and im worried about her....