Should we have gained weight yet or am I eating too much?

Hey guys! I was 5'9 and 160 when I conceived. I'm 7 and a half weeks now and have already gained 4 pounds. Is this too much already ? Am I eating too much? I feel like most of it is in my boobs! I worked out before I got pregnant but now I'm just so exhausted that I can't get my butt to the gym. What do you guys think?