I'm really sorry for the pressure you are feeling. All you should have to do is worry about getting through your pregnancy happily and healthily. Yes weight is a factor and no you don't want to be putting on excessive amounts but you should not be made to stress about these things.

2kg is rediculous!!!! In my opinion anyway. I am a relitively small person and i put on 17ish kg each pregnancy. A lot of it was baby and i managed to loose it once i was able to think about myself. Months after baby was born.

And not sure if it'll make you feel any better or not but even before children when i was going to the gym and exercising all i liked my BMI was always high. It's just me.

Just focus on being healthy for yourself and your baby. Try (i know it's hard) to block out those silly Dr's and nurses