Cats usually give birth in about two months of pregnancy. Counting from the first day of successful mating of kittens, the period of pregnancy is approximately 62 to 67 days, with an average of 65 days. If the baby is born earlier than 58 days, the kitten is likely to die prematurely or be weak during delivery, which is considered premature birth. Kittens born after 71 days may be larger than normal and may die in infancy. Therefore, if the cat has not given birth in about 70 days, it is best to take it to a pet hospital to consult a professional pet doctor.

Methods to determine when a cat will give birth after she is pregnant:

1. Observe the cat’s behavioral changes before giving birth. Some cats may become unsociable, but most cats will become more clingy than before.

2. Observe whether the cat’s appetite has decreased. Cats will suddenly lose their appetite a few days or hours before giving birth. This is most likely due to the kitten's peristalsis in the uterus squeezing the mother cat's stomach, causing a loss of appetite, or it may be caused by the mother cat's anxiety about giving birth.

3. Observe whether the cat has colostrum secretion. Usually begins 24–48 hours before kittens are born. You can see some thick beige discharge from its nipples. This is colostrum.

4. Observe whether the cat starts to look for a nest. Some cats may start nesting weeks before giving birth, while others may only do so on the last day.

5. Measure the cat’s body temperature. Cats' normal body temperatures are higher than ours. Usually between 37.7–39.1°C. One or two days before birth, the body temperature of pregnant cats will drop a bit, usually to below 37.7°C.