Anyone else have a huge belly already but haven’t gained a single pound?

I’ve actually lost 7 pounds since I found out I’m pregnant. I’ve been eating much more than usual. It hasn’t been all the ‘best pregnancy foods’ either. Don’t get me wrong, I do usually eat pretty healthy, my husband and I are pescetarians (the only meat we eat is fish, and that’s only once a week). But recently I’ve been eating ice cream and cheese and pasta. My belly is getting bigger every day it seems but still no weight gain. I’m 13w4d with our baby boy today. Is anyone else in the same boat?