I've BTDT w/ #2 and everything was FINE. My fundal height dropped off over the course of a month, when it got to be a full 4cm smaller than it should have been, my Dr. did an US to check for IUGR. Basically they check to make sure baby is growing consistantly, not a big head and small body. My DD was fine, but she did measure smaller than her dates, but my Dr was fine w/ that, as long as she was growing. You might also ask about doing a NST, where they watch baby's HR for about 20 minutes and make sure she's having accels and decels. Good luck and think positive! Oh, and thtat DD is still really small, even at age 2. She's just petite. My first was 8lb4oz, second was 1/2 oz shy of 7lbs. Everyone is different!