Is it normal for cats to have silent heat cycles? I have heard everyone say that they should go into heat around a week after the babies are born. Well the babies are almost 2 weeks old and she hasn't gone into heat. As a matter of fact I have never heard her go into heat. I have had her for almost a year. And she has never gone into heat. But, I wasn't watching for it either because I thought she was spade, which of course she wasn't. But, I think I would have noticed if she was in heat. So, I think my cat has silent heat cycles, is this normal???