I think it's much more likely that you're either extremely bloated or are experiencing some freak attack of gas. There's no possible way your baby (or uterus) are big enough to make your stomach stick out like that, especially lying down. You either have a tumor the size of a grapefruit in there or you're bloated.
I can sympathize. I'm 7 weeks along and my stomach's massively too big. Of course, this is my second pregnancy and I recognize my growth for exactly what it is: bloating.
I understand how excited you are to be pregnant, but in all honesty, that's not your baby belly you're showing off there. That's unfortunate water gain or the result of "eating for two". I'm not trying to be cruel to you, just honest. You probably won't start truly showing until your baby and uterus are big enough to actually make contact with your stomach, which starts around week 20 or so. Until then, drink plenty of water to help control the bloating and watch your calorie intake.