It was probably just bloating. Until 12 weeks your baby is too small to be seen and your uterus is still not above your pubic bone .
I'm sure your fine. You uterus is still behind your pelvic bone and doesn't start to rise up untill about 12 weeks. I'm 14 weeks and I still don't have a bump.
That happened to me too and now I'm 30 wks with a perfectly healthy little girl :) your fine