No def not bad especially being over weight before. Your dr will actually prob be happy about it. As long as your baby is growing and healthy then weight loss during preg is not a bad thing. I have a friend who the dr only wanted to gain only 15 lbs max and she lost weight throughout most her preg and only gained 8 lbs at the end. Her dr was very pleased. Just make sure you are getting enough vitamines
I wouldn't worry about it just yet,.my first 16 weeks I lost just over ten pounds from all the morning sickness and from living a healthier lifestyle, I'm 20+ 5 and I've gained back 6 pounds. They say you gain most later on, so you never quite know just how much you'll gain.
I did that with my second son, I ended up only gaining 13 lbs . he was 7 lbs 14 oz and I was a little over weight too start with to. It's normal :)