I think its better to wait until your bleeding stops, I had a c-section and was bleeding for 4 weeks and when my bleeding was stopping I started to do more stuff around the house and my bleeding came back bright red color, sometimes when I felt its coming I ran to the toilet and it was pouring out, I think I overdid it, walking is ok but not too much, listen to your body and don't push yourself!
It's been 4 weeks today since my csection and I've already started exercising. I think if you feel up to it then you should. Just take it easy and don't push yourself too hard. =)