Can diet and excersize have a negative effect ?

We always recommend that your activity should not differ from the non pregnant state to the pregnant. In other words, if you don't exercise, it wouldn't be wise to start doing so in pregnancy. If you continually excersize, then it's ok to continue while you're trying to get pregnant and onto pregnancy (of note, you shouldn't excersize to the point you stop having periods if trying to get pregnant :) If you keep your heart rate below 140 which will still give you a great work-out and slow down the pace to where it's a longer aerobic work-out and still get to burn an equal amount of calories, you'll see you'll be able to keep your heart rate below this and not increase your body temp tremendously that a faster quicker aerobic exercise can do. Hope this info helps, k.