Babys far south

Since my first doctors appointment the doctor told me baby is very far down. At my 17 week appointment we did another quick ultrasound to see if they had moved and theyre still very far down. My doctor seemed almost worried about it. Now im 21 weeks tomorrow and the only spot i feel movement is as far down as possible basically. Im just curious if anyone else has had that happen in past pregnancies. Is it something to worry about? My daughter was always smack dab in the middle.