I am 34 years old, 5'7" tall, weigh 147 pounds and am 8 weeks pregnant with my 6th (yes, you read that right, 6th) child. I have been exercising regularly (6 days a week) and am in better physical condition than I have been with any previous pregnancy. My question is, since hitting the 6 week mark, I have felt constantly dizzy, and when I exercise the way I have been for the past year, I lose weight. I am not restricting calories, nor am I gorging myself. Is it something to be concerned with at this stage of the pregnancy?