Trouble gaining weight

Hey everyone ,

So as you can see from the title i seem to be having trouble gaining weight I’m 12 weeks babies are growing as they should and beats are good but I seem to be staying the same weight 147 and I look like I’m getting more sunken in in the face I am eating but small portions only because I get full so fast but I just can’t seem to figure it out ob said they are doing great but she also asked if I was eating because I seem to be the same weight from when o started any tips ?

Thank you girls❤️