After approximately 15-18 days of a cat pregnancy, you may notice that your pet’s nipples become enlarged and red – this is known as ‘pinking-up’. Similar to morning sickness in humans, your cat may go through a stage of vomiting. Your cat's tummy will start to swell. A mum-to-be will gradually gain between 1-2 kg (depending on the number of kittens she is carrying) - this is a strong sign that she is pregnant. Cats tend to have an increased appetite later in their pregnancy, which will also contribute towards her weight gain. Your pregnant cat may act more maternal, meaning that she purrs more and seeks extra fuss and attention from you.