Am i gaining too much

Im 12w6d and ive already gained like 6-8 pounds and im starting to show already. Theres another prego at work who is 13w2d and she lost 4 pounds and is not showing at all. 
Im worried im gna blow up like a blimp. We eat about the same amount of food except she was getting morning sickness really bad sometimes and i didnt have it at all so i guess there were days i ate more than her.
I dont want to be huge!! Im still working out when im not too tired.