6th percentile for body weight

Soooo.... I am officially 9 months (36 weeks and 3 days). Mia and I had our ultrasound appt and then OBGYN appt right after. They weighed her and measured her --- 5lbs even.... They said not to worry because the placenta and umbilical cord look great. She's just teenie tiny like me. But to take precaution, I now have to get an ultrasound every Tuesday and Friday until the c-section. Any one else having this experience?