Anyone supposed to have a "small baby"

I'm 35 weeks and my doctor says the baby is only in the 22nd percentile size-wise. He is having me go in to another office for a scan to get a better reading. He says she is healthy and is doing everything she should (fetal breathing) and that he is being ocd and thorough. I love that he does things like this to be on the safe side but I just think it's odd he would send me to a specialist for an ultrasound when everything looks great. She's considered to be in a normal range and she's grown every scan. I still have a month left for her to grow and she gained around 3oz since last week's scan (he did an ultrasound yesterday). Does anyone else have an extremely thorough doctor? If you're having/ had a smaller baby in the "normal range", did your care provider take extra precaution?