No, that's perfectly fine. A lot of women lose weight in their first trimester from morning sickness. I've heard of women losing 15lbs! As for overweight and developing a healthy lifestyle most doctors recommend it. I'm a bit over weight and my Midwife and I are going to work out a schedule, meal plan, and exercise routine with a personal trainer so that I can lose weight the healthy way during this pregnancy. I had my son 6 months ago and gained 50lbs with him. I've only lost 25lbs since he was born so I still have a bit to lose and my Midwife said it's perfectly fine as long as I do it the safe way. As long as you're not stressing your body and getting the right amount of healthy calories you're good.