Our family cat was recently hit on the road after having a litter of 3 kittens. There is one little boy left, who is now 3 weeks old that I am attempting to take care of. He is eating very well and pees after every feeding, but he hasn't pooped at all and I've been taking care of him for 4 days. His tummy is fat, but it's still soft, so I don't think he's constipated. I have been trying to stimulate him with both wet and dry cloths, but nothing is working.
What should I do?