A lot of it could be water bloat weight. I'm 11 w 4 days and have gained 6. I also rely on my scale more than the doctors. He weights me at 4 pm after lunch and stuff!!! Lol. I find that getting in a small workout removes the bloat and the weight. Even just walking 20-30 minutes each day. You'll beokay. :)
I wouldn't stress about it. If u have no complications moderate exercise in general is great throughout ur pregnancy.