Another Ultrasound????

So, I'm having ANOTHER ultrasound in 4 weeks. After meeting with my doc today, he said baby looked good....organs healthy, etc, but he said the baby's body was measuring differently in different parts. The head/abdomen were measuring a few weeks ahead and the femur was measuring small.......so what does that mean??? Nothing right now except I may be loading up on drugs for this child's big head to come out in a few months!! :) Seriously though...the doc just wants to see if he "evens out" in the next few weeks and then we will go from there! I just think of it as another chance to get a look at my growing boy, so that will be fun.