dying to workout

I'm almost 3 weeks pp. I had a super healthy pregnancy. I ran 5-6 days a week, including the night before going into labor. I had a short labor, 3.5 hours, no tears/stiches. I gained 32 lbs, and lost 18 of those within 2 weeks pp. I am dying to workout again. I know walking is ok, but I'm stuck inside (snow outside), and walking around my house isn't cutting it! any workout tips? fellow runners. how long before you began running again???