Its baby bloat. I am about the same size as you and now at 12 weeks. I started wearing my belly band several weeks ago. Yesterday I wore a pair of maternity pants (probably too early but super comfy!). You are bloated because you are pregnant -- it is not a bad thing. Just uncomfortable.
I can tell that most (all?) is still bloat because it gets bigger as the day goes on. The baby itself is still very tiny and your uterus is behind your pubic bone so its not showing anything yet.
Each time I go to the OB, I have them show me where my uterus is. As of a few days ago, my uterus was only a few inches above my pubic bone. I wear what is comfortable (belly band) and not worry about if it is too early. I am not going to uncomfortable all day.