Trying to not be depressed

Just found out that a friend of mine who is due in November has only gained 3 pounds so far. It's her first baby, this is my third. I've already gained 15-17 pounds and an 18.5 weeks! I just feel really bad about myself at the moment. I'm not being unhealthy. I exercise 5 days a week and eat right. Yes, I indulge here and there, but I'm not going crazy. Anyone else gaining a lot this quickly? I feel hopeless and hate hearing about other people who seem to be having the perfect pregnancy as far as weight gain.