I wouldnt worry... my first PG I dodnt start showing until 27 weeks PG! nobody believed me when I told them I was pregnant then one day I woke up with a nice round belly LOL I have no idea how it happens but sometimes people seem to just "pop out". I put on 12kg with my first PG.

I actually weighed myself 2 days ago & I am now 1kg heavier than when I fell pregnant. I know I lost weight in the first trimester so I've put on more than just 1kg as I've made up for the weight I lost.

Maybe somewhere along the way you lost a few kilos & have put it back on plus the extra 2kg IYKWIM? & maybe you have only put on 2kg which is also fine.

I would still bring it up with your midwife/carer just to put your mind at ease.