Carrying low/high?

Is there anything that determines how you carry? Does it have to do just with a person's body? My friend and I are due the same day -- and no we are not a part of the pact in M... we are well into our 20s thanks-- and look so different. Her belly is large and round and she can't fit into her clothes anymore. My belly is pretty small, low, and I can still on my pants!