Sometimes a doe will let a buck breed her when she is already pregnant. A friend had a doe that was bred, but escaped from her cage. The buck was out too so he could hop around while they cleaned out his cage. Anyway, he bred her. A week later, she had her kits, and then another week later she had 12 more tiny ones. The 12 were dead but the first litter was alright. Maybe that won't happen. Make sure she has a nestbox just incase.