someone help me out here 😫🤔

May • First time Mom 💕
In the last 6 months I've literally only gained 4kg, is there something I'm doing wrong?  My stomach just looks like I've been eating good but no one can tell I'm 6 months pregnant even though the doctor and ultrasounds say there's absolutely nothing wrong with my baby, I still worry that this might not be "normal", or am I just paranoid 😩😫