15 weeks 2 days - where did that come from?!

So I had an ultrasound today to make sure that baby was okay as the Doctor still couldn't find a heart beat on the doppler. No good pictures of baby's profile but the little one sure was moving around and definitely alive! My big surprise/almost scare today was when I first saw my full self in the mirror and whamo there is this huge baby belly! Where did that come from? I kind of feel like there isn't enough room for me to put food in my stomach or even take a full breath, which could be slightly problematic as I still haven't actually gained any weight this pregnancy.