yes its bloating. At six weeks your baby is teeny teeny tiny. I got really bloated early in my preg. also. It should go away eventually. Try to stay away from really salty foods and drink LOTS of water. Im just now starting to show and im 14 wks. Bloating happens to all of us...one of the many exciting things pregnancy brings

if you're only 6wks, it's bloating. Even if you had 10 babies in there, they wouldn't look that big from just them. Weird thing is, I looked like that at about 15wks

Most likely bloating like everyone said. I was bigger at 8 weeks then I am now at 14 weeks because of bloating. Your uterus is still sitting wayy below your pubic bone and wouldn't be large enough for you to show at all. And you also said you gained 12 pounds so far...I imagine that might be what it is as well