I went from lifting heavly and running 6-7 days a week to hoping to do some sort of cardio 4-5 days a week while I'm pregnant.  I am trying to be realistic and understand that my body is undergoing a lot of changes.  Working out is my outlet and it helps me sleep better but I am just feeling so drained.  My doctor said to continue to do what I have been doing as long as it feels good.  No maxing out of corse but continue.