Help!!!!!

Ok so my cat is about 3 and a half. We are pretty sure she is pregnant. Earlier I went up to take a bath and was gone for about 20 mins. When I got back there was a big wet spot on the bed and little black pellets all over. At first I thought her water might of broke but what about the pellets? Please does anyone know what might be going on???

Ok so never mind a couple of baby bunnies got in. She killed one but I managed to save the other