hip dysplasia

hi everyone. Just wondered if any could give me some real info. (symptoms, ect) Maybe u have been through this yourself or might know a baby with hip dysplasia. My daughter is my 3rd child and was born 7 weeks early. She is bow 17week old. I've always noticed she has an extra roll of chubbiness on her right leg. But yesterday I noticed her right leg is about 1.5cm longer than her left leg. after closely investigating more. her right hip looks lower than the left. her right thigh is chubbier than the left. shes not flexible at all. and her bum creases are really asymmetrical. im making a doc appointment first thing monday. Any advice is welcome and thank u in advance.