Fetal weight percentile question

[Ashersmomma]

Ok, so I wasn't really worried too much about LOs size, since the OB I saw said everything looked good. It was a different OB than I usually see because my insurance only covers a certain number of ultrasounds.(My OB just schedules me at a different clinic to get around that) This OB didn't mention anything about the percentiles, just told me weight. At 27w2d she was 2lb 1oz and at this last one(31w2d) she was 3lb 8oz.
I just looked up the percentiles on those weights and she was in the 36th percentile at the 27w ultrasound and in the 26th percentile at this last one. I know weights can be off on ultrasounds. Should I be worried about her dropping by 10 percent in just 4 weeks or is this normal? My DS was a bigger baby and I have no experience with babies measuring smaller.
Oh, and they didn't say anything during the ultrasound, but I did notice when they were doing measurements that her head and abdomen were measuring between 31-32w, but her femur was right around 29w? (That's what popped up in their little measurement box thing) Is that fairly normal?

 

[Dobsd]

My LO was in the 91st percentile at 26 weeks and then 82nd at 31 weeks. Midwife was unconcerned and said everything was fine.

Ps - my baby is quite big as I'm pretty tall and apparently she has long legs!

 

[Bakebino]

I am going through this exact scenario right now and the doctor is concerned. At 31+3 baby was estimated to weigh 3lbs 12oz, 36th percentile. Today at 35+4 shes estimated at 5lbs 6oz, 20th percentile. He said generally they don't get concerned until baby is at or below the 10th percentile, but 14% is a big drop for just 4 weeks time. They also think my fluid is on the low end of normal. Starting Monday I have to have twice weekly non stress tests to check and make sure lo is ok. The plan was to do a csection at 39+1 but the doc today thinks that may be too ambitious. I have my 36 week appt with my regular OB on Monday so we will see what she thinks.

 

[Ashersmomma]

Thanks ladies. I have an appointment with my regular OB on Tuesday and will bring it up with him to see what he thinks.