Alright Mandy because I respect you... I will tell you the truth and not worry about sparing your feelings... k? If you ready for that then read on...
Girl, are you nuts? 
You can most certainly tell you are pregnant! You do not look "fat" -- you can SO tell that is a baby filled tummy and not a pizza jelly donut filled tummy.
The dress does look to big tho, I agree that it needs to be haltered. But I definitely disagree and think you are nuts on looking fat!