It's most likely still bloat I'm afraid (you don't need to eat to be bloated, it's about fluid retention) as at 10 weeks your uterus hasn't risen above your pubic bone yet. If you've had a baby before then you might be showing, as second and more babies show earlier as the uterus rises quicker out of the pelvic cavity. The soreness will definitely be your uterus growing.
I remember being really anxious for my bump my first pregnancy, but I didn't get one till around 20 weeks (tiny round bump) and no one even noticed it until 26 weeks when it started sticking out more. I was really slim and had good stomach muscles, which kept it all together. With my second I was still slim and got the rounding around 18 weeks, with the proper bump showing around 24 week as my stomach muscles were weaker. The next time I imagine I'll show even sooner as after having two already and having so little time to exercise, my stomach tone is sadly nowhere near as good. It is exciting getting a bump!
Hope you get yours soon.