It is normal preggy mum have little gain to lots of weight gain. All of these are either because of water rentention, inclusive baby's weight it or body hormonal changes due to pregnancy. I believe in proper confinement, food intake, massage pre/post and also exercising once you give birth. One way or another it helps to shed weight. But boils down to individual body and I do agree on different body types will have different gain and lose.
I have gained 14kg. I am at 36wks. I think you shouldn't worry abt weight at this point mama. Importantly baby and you are healthy. We can work on our weight after
im also currently week 35 day1 and had gained 20kgs. hopefully everything sheds off after giving birth.