forgot to mention I am 5'4" too so weight shows up on me differently then someone that is taller--- I gain 10 lbs and it is noticeable :D
don't feel bad at all I have gained 13 pounds and I am 20 weeks. Every woman gains weight differently when they are pregnant. My first 4-5 months I look just fat until I pop. So don't feel bad, just trust your body is providing your baby what it needs :)
do they not know you're pregnant? well, i wouldn't worry about it. like you said, you're gaining weight for a good reason. and 5-6lbs is nothing, especially if you're 18 weeks along. best of luck and well wishes on a healthy pregnancy and baby! :)
Yeah I agree with that judging by your photos u look very thin to me