Female cats cannot become pregnant if they are not in heat. If a female cat is not in estrus, she will not ovulate. The purpose of estrus is to promote ovulation, which is a physiological and instinctive reaction. If the female cat is not in estrus and is forced to mate, it will also cause an excessive reaction in the female cat.

Symptoms of a female cat in estrus:

1. The most obvious sign of a female cat in estrus is meowing all day long, with a high-pitched and unpleasant sound. Especially in the middle of the night, they will scream very frequently and loudly.

2. The temperament of a female cat changes drastically. When the female cat is in heat, she becomes irritable and restless. Sometimes when the owner approaches her, she will become extremely restless and scratch.

3. The external characteristics of a female cat in estrus are swelling of the vulva, and there will be some transparent and sticky secretions.

4. Female cats will often stick out their buttocks to spread their scent further and attract nearby male cats to mate.

5. The female cat may run away from home and may be pregnant when she comes back.