I agree with Kate about taking it easy at first. They don't just say that for a reason. I believe it is even dangerous for you to exercise right away because of your uterus. It needs time to get back to its regular size, which takes a few weeks; faster if you nurse. I remember trying to exercise right away with my 2nd baby and I got bad belly cramps (gas?)every time. It was very very painful. Just keep busy - which you will - and you will one day just feel that the time is right for you to ease back into it. I would say about 4 weeks, but that is if you don't have a c-section and I know the dr. will tell you probably 6-8 weeks. I never listened to my doctor exactly, though...